FAQ | Rotavirus disease and vaccines – Rotavirus Vaccine Access and Delivery

FAQ | Rotavirus disease and vaccines

Rotavirus FAQs Read the full text as a PDF: English [289 KB] | French [278 KB]

Rotavirus disease
Rotavirus vaccines
Rotavirus vaccine safety and potential side effects
References

Rotavirus disease

What is rotavirus?

Rotavirus is a virus that causes gastroenteritis—an inflammation of the stomach and intestines. It is the leading cause of severe and fatal diarrhea in young children worldwide and can also cause vomiting and fever. If left untreated, it can lead to severe dehydration and death.

How many young children die from or are hospitalized for rotavirus each year?

Globally, rotavirus is responsible for more than 450,000 deaths each year in children younger than five years of age—more than 1,200 each day—and is responsible for millions of hospitalizations and clinic visits each year.^1,2 It affects children around the world in rich and poor countries alike. While rotavirus deaths and hospitalizations vary by region and country, the vast majority (95 percent) of rotavirus deaths in young children are found in GAVI-eligible, low-income countries in Africa and Asia.¹ Five percent of all deaths in children younger than five years of age are due to rotavirus.¹

What percentage of diarrhea deaths and diarrhea-related hospitalizations are due to rotavirus?

Rotavirus is estimated to cause approximately 40 percent of the 1.3 million diarrheal deaths and 9 million diarrhea-related hospitalizations in children under five years of age worldwide.^2,3

Who is at risk for rotavirus infection?

Nearly every child is at risk of infection, regardless of where he/she lives, his/her hygiene practices, or access to safe drinking water or sanitation. Children six months to two years of age are most vulnerable to infection, along with premature infants, the elderly, and those with weakened immune systems.

Vaccinated and unvaccinated children may develop rotavirus disease more than once because there are many different types of rotavirus, and because neither the vaccine nor natural infection provides full immunity (protection) from future infections. Usually a person’s first infection with rotavirus causes the most severe symptoms.

What are the symptoms of rotavirus?

Once a person has been exposed to rotavirus, it takes about two days for symptoms to appear. Symptoms include diarrhea, vomiting, fever, and abdominal pain.

Vomiting and watery diarrhea may last from three to eight days in a child infected with rotavirus. Additional symptoms include loss of appetite and dehydration, which can be especially harmful for young children and lead to death.

How is rotavirus spread?

Rotavirus is shed (passed from a person’s body into the environment) in feces (stool) of infected persons. The virus spreads by the fecal–oral route; this means that the virus must be shed by an infected person in his/her feces and then enter a susceptible person’s mouth to cause infection. Rotavirus is highly contagious and resilient. It spreads easily from person to person through contaminated hands and objects, such as toys and surfaces.

Rotavirus can live on contaminated hands for hours and surfaces for days. Children can spread the virus both before and after they become sick with diarrhea. They also can pass rotavirus to family members and other people with whom they have close contact.

What is the treatment for rotavirus?

Rotavirus cannot be treated with antibiotics or other drugs. Mild rotavirus infections can be treated effectively in the same manner as other forms of diarrhea, by providing fluids and salts (oral rehydration therapy) until the disease runs its course. However, children with severe rotavirus diarrhea urgently need intravenous fluids, or they risk dying from dehydration. In developing countries, this type of urgent health care is often inaccessible or unavailable, making rotavirus prevention through vaccination critical to saving children’s lives.

How can we prevent rotavirus?

Vaccination against rotavirus is the best method of prevention available. Improvements in hygiene, water quality, and sanitation that stop many bacteria and parasites that cause diarrhea do not adequately prevent the transmission of rotavirus.⁴ Rotavirus vaccines should be introduced as part of a comprehensive approach to control all causes of diarrhea, along with interventions including oral rehydration therapy, zinc supplementation, breastfeeding, improvements in water, sanitation, and hygiene, as well as proper nutrition.^5,6

How big a threat is rotavirus to children’s health and well-being?

Rotavirus is one of the deadliest diseases for children in the developing world and is the most common cause of severe diarrhea in children. Rotavirus is estimated to cause approximately 40 percent of diarrheal deaths in children under age five worldwide and kills more than 450,000 of these children each year.¹ It also causes about 40 percent of all hospitalizations for diarrheal disease in children under age five worldwide.³ It is particularly lethal in places where urgent medical care is out of reach. The best way to protect these vulnerable children is through vaccination.

Where can I find more information on rotavirus disease?

More information on rotavirus disease is available from the US Centers for Disease Control and Prevention (CDC).

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Rotavirus vaccines

Why are rotavirus vaccines needed/necessary?

Vaccines are the best way to protect children from rotavirus and the deadly dehydrating diarrhea that it causes. Improvements in hygiene, water quality, and sanitation that stop many bacteria and parasites that cause diarrhea do not adequately prevent the transmission of rotavirus.⁴ Rotavirus vaccines are key to a comprehensive approach to reduce the impact of diarrheal disease. Introducing rotavirus vaccines with other diarrhea prevention and treatment methods, such as oral rehydration therapy, zinc supplementation, breastfeeding, improved hygiene, water quality, sanitation, and nutrition, can significantly reduce child illnesses and deaths.^5,6

What rotavirus vaccines are available?

There are two orally-administered rotavirus vaccines available today: Rotarix^®, manufactured by GlaxoSmithKline (GSK) and RotaTeq^®, manufactured by Merck & Co. Inc. Both vaccines have been shown to be safe and effective in large-scale clinical trials in Africa, Asia, Europe, Latin America, and the US.^{7–10,13–16}

New vaccines that could be available as soon as 2014 or 2015 are being developed by manufacturers in India, China, and Brazil. In addition to making more vaccines available, these new vaccines could help make rotavirus vaccines more affordable by creating a more competitive marketplace.

How are rotavirus vaccines administered to children?

Both rotavirus vaccines are given orally but differ in the number of doses given. Each country has its own immunization schedule. In general, in lower income countries, RotaTeq^® is given in three doses at 6 weeks, 10 weeks, and 14 weeks of age, and Rotarix^® is given in two doses at 10 weeks and 14 weeks of age. In middle and upper income countries, RotaTeq^® is given in three doses at 2 months, 4 months, and 6 months of age, and Rotarix^® is given in two doses at 2 months and 4 months of age.

When did rotavirus vaccines become available and prequalified by the WHO?

The FDA licensed Merck’s RotaTeq^® in February of 2006 and GSK’s Rotarix^® in April of 2008. The European Commission and the European Medicines Agency (EMA) licensed GSK’s Rotarix^® in February 2006 and Merck’s RotaTeq^® in June 2006. WHO first prequalified Rotarix^® in January 2007 and RotaTeq^® in October 2008.

Was there another/earlier rotavirus vaccine? What about RotaShield^®?

RotaShield^® was the first rotavirus vaccine available in the US in 1998. Intussusception was found to be a rare but potential side effect (1 out of every 10,000 infants). As a result, RotaShield^® was voluntarily withdrawn from the market by the manufacturer in 1999.

Are some countries now using rotavirus vaccines? What is WHO’s recommendation?

The WHO recommends that rotavirus vaccines be introduced into every country’s national immunization program, particularly in countries where diarrheal disease is a major health problem.⁵ As of April 27, 2013, 45 countries—mostly middle-and high-income countries—have introduced rotavirus vaccines in their national immunization programs (i.e., public sector). Other countries, such as Canada, Thailand, and Zambia have introduced rotavirus vaccines in pilot or regional introductions. Routine, public-sector use of rotavirus vaccines in low-income, GAVI-eligible countries is limited but expanding. Rotavirus vaccines are also available in more than 100 countries through the private market.

Which GAVI-eligible countries have introduced rotavirus vaccines?

GAVI began offering support for rotavirus vaccines in 2006. Since then, rotavirus vaccines have been introduced in Nicaragua (2006), Bolivia (2008), Honduras (2009), Guyana (2010), Sudan (2011), Ghana (2012), Rwanda (2012), Moldova (2012), Yemen (2012), Armenia (2012), Malawi (2012), Tanzania (2012), Georgia (2013), and Haiti (2013) with GAVI support.

Will GAVI support the introduction of rotavirus vaccines in more countries?

GAVI has approved 20 additional countries for rotavirus vaccine support including: Angola, Burkina Faso, Burundi, Cameroon, Central Africa Republic, Republic of the Congo, Djibouti, Eritrea, Ethiopia, Gambia, Guinea-Bissau, Kenya, Madagascar, Mali, Niger, Sierra Leone, Togo, Uzbekistan, Zambia, and Zimbabwe.

By 2015, GAVI and its partners plan to support at least 40 countries in introducing rotavirus vaccines—immunizing 50 million more children.

Are rotavirus vaccines cost-effective?

Rotavirus vaccines are cost-effective and not only improve child health, but they also save lives. Vaccination lessens the tremendous economic and health burden of rotavirus disease, thereby contributing to poverty reduction and a growing economy.

How many lives can be saved with these vaccines?

In GAVI-eligible countries, where 95 percent of deaths due to rotavirus occur, more than 2.4 million child deaths can be prevented by 2030 by accelerating access to lifesaving rotavirus vaccines.¹¹ If used in all GAVI-eligible countries, rotavirus vaccines could prevent an estimated 180,000 deaths and avert 6 million clinic and hospital visits each year, thereby saving US$68 million annually in treatment costs.¹¹

Does the vaccine provide 100 percent protection against rotavirus?

While no medical intervention or product is 100 percent effective, rotavirus vaccines do provide the best protection available today against rotavirus, the most common cause of severe, deadly diarrhea. They are particularly important since improved hygiene, sanitation, and safe drinking water alone cannot adequately prevent rotavirus.

Can you still get rotavirus even with the vaccine?

Research suggests that rotavirus vaccines are most effective at preventing the most severe and life-threatening cases of rotavirus.¹² A small proportion of vaccinated infants may develop rotavirus disease more than once because neither the vaccine nor natural infection provides full immunity (protection) from future infections and there are many different types of rotavirus. Usually a person’s first infection with rotavirus causes the most severe symptoms.

Are rotavirus vaccines effective in both industrialized and developing countries?

Yes. Clinical studies have shown that rotavirus vaccine efficacy against severe rotavirus during the first year of life has ranged from 85 to 98 percent in industrialized countries, ^13–16 including in Latin America, and 51 to 64 percent in developing countries in Africa and Asia.^8–10 On the basis of efficacy data from Europe and America, the WHO initially approved use of the vaccines in these regions in 2006.¹⁷ Subsequently, after proof of efficacy in Asia and Africa, the WHO recommended that rotavirus vaccines be introduced into every country’s national immunization program, particularly in countries where diarrheal disease is a major health problem.⁵

Why is rotavirus vaccine efficacy different between high-income and low-income countries?

Data from clinical studies in middle- and high-income countries demonstrate higher vaccine efficacy, which may be due to a range of factors (see below).^18,19 The Accelerated Vaccine Introduction Technical Assistance Consortium, PATH, and others are studying these factors so that national health ministries will ultimately be able to optimize rotavirus vaccination strategies and provide children the best possible protection.

What factors may have contributed to lower efficacy rates observed in clinical studies in Africa and Asia?

Lower efficacy of oral vaccines is typical in impoverished, high-mortality settings. This is seen with other orally administered vaccines like polio, cholera, and typhoid. Several factors may contribute to lower efficacy, such as the age of the child when the vaccine is administered, possible interference by maternal antibodies, micronutrient deficiencies, persistent exposure to pathogens, higher prevalence of co-infections, or wide varieties of virus strains.^18,19

Will rotavirus vaccines be useful in developing countries even if the efficacy is lower?

Although in some clinical trials lower vaccine efficacy was observed in certain developing countries compared with data from industrialized countries, rotavirus vaccines are expected to have a major public health impact in where the rotavirus burden is greatest—such as in developing countries in Africa and Asia.^12,20 Efficacy is only one factor in assessing the potential impact of a vaccine; the other critical factor is the incidence of severe disease. The vaccine likely will have a greater impact than we have seen elsewhere, even at a lower efficacy rate, because rotavirus vaccines will still substantially reduce severe cases of rotavirus diarrhea—those that are most life threatening.^12,20

Will future rotavirus vaccines have better efficacy in the developing world?

There are new rotavirus vaccine candidates currently in development in India, China, and Brazil. The characteristics of these vaccines vary—some are live, attenuated vaccines, some are inactivated—and their efficacy has not yet been evaluated. When new rotavirus vaccines do become available, vulnerable populations will benefit from additional options and a healthy marketplace that will ultimately drive down vaccine prices.

How long do rotavirus vaccines provide protection against rotavirus?

In developed countries, rotavirus vaccines have been shown to protect infants who receive the vaccine before they reach 8 months of age in both the first and second years of life.

In the developing world, the rotavirus threat is greatest during the first year of life. In clinical studies in Africa and Asia, rotavirus vaccines have been shown to provide the greatest protection during this first year.^8–10 Efficacy in the second year of life appears to be lower in developing countries, but further evaluation is required to understand in which populations and under what circumstances vaccine efficacy declines.^8–10

Does vaccine efficacy decline over time?

What is the most important information that parents and caregivers of children should know about rotavirus vaccines?

The benefits of rotavirus vaccination are substantial—preventing hospitalizations and deaths from diarrhea. The benefits of these vaccines far exceed any possible low-level risks associated with the vaccine.^{21,23,24,30–32}

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Rotavirus vaccine safety and potential side effects

Are rotavirus vaccines safe?

Both Rotarix^®, manufactured by GlaxoSmithKline (GSK) and RotaTeq^®, manufactured by Merck & Co. Inc. have been shown to be safe and effective in large-scale clinical trials in Africa, Asia, Europe, Latin America, and the US.^{7–9,13–16} The WHO recommends that rotavirus vaccines be introduced by every country.⁵ Recent studies have consistently demonstrated the swift and significant impact of these vaccines to lower hospitalization and death rates from severe and fatal diarrhea.²² Both vaccines on the market today have strong safety records and the benefits of these vaccines are substantial and far exceed any possible low-level risks.^{21,23,24,30–32}

What are potential side effects?

Most children who get vaccinated will not experience any side effects. However, there is a slight chance of a few minor symptoms, which include diarrhea, vomiting, and irritability. In rare cases, intussusception, a folding of the bowel, has been associated with vaccination. The risk of any vaccine causing serious harm is extremely small and the benefits of rotavirus vaccination are substantial and far exceed any possible low-level risks.^{21,23,24,30–32}

What is intussusception?

Intussusception is when one portion of the bowel slides into the next, much like the pieces of a telescope. When this occurs, it creates a blockage in the bowel. If it is not detected early, internal bleeding, a hole in the intestines, and infection in the abdomen may occur because the intestinal tissue has died from the decreased blood flow. In some cases surgery might be required.

What causes intussusception and who is susceptible to intussusception?

Intussusception occurs naturally for unknown reasons in about 1 child per 10,000. Some cases may be caused by a bowel infection. Some cases may be caused by a polyp or tumor in the bowel—both of these are groups of cells growing in the bowel that are not normal. However, some studies have shown a small increase in cases of intussusception within a week after the first or second dose of rotavirus vaccine.^21,25 People of any age can get intussusception, although it is most common among infants in the first year of life, generally between the ages of 5 and 9 months. Studies have found a higher incidence among boys.

How is intussusception diagnosed and treated?

Intussusception can be detected by examining the abdomen or performing an ultrasound. The best test is a special enema study, where liquid and/or air is put into the back passage using a catheter. This test is usually done in a hospital. The test is often successful in unblocking the bowel and the baby can usually go home after a short period of observation. In about 30 percent of cases, an operation is needed to unblock the bowel. After surgery, babies will need to stay in hospital for a few days and be given intravenous fluids until able to feed normally.

Do rotavirus vaccines cause intussusception?

Intussusception was found to be a side effect of the first rotavirus vaccine available in the United States, RotaShield^®, which was recommended for use in October 1998. As a result, that vaccine was voluntarily withdrawn from the market by the manufacturer in October 1999. That vaccine was estimated to cause intussusception in 1 infant out of every 10,000 infants who received it.

The risk of intussusception with newer rotavirus vaccines (Rotarix^® and RotaTeq^®) was assessed in large clinical trials prior to licensure in the US, Finland, and Latin America. Each trial involved more than 70,000 participants and no increased risk for intussusception was observed. Researchers found that the risk of intussusception was similar among children who received the vaccine and those who received a placebo, indicating that the currently available vaccines are safe for use.^13,15

Although neither Rotarix^® or RotaTeq^® was associated with intussusception during the clinical trials, post-marketing surveillance of rotavirus vaccine immunization has indicated a possibility of a small increased risk of intussusception shortly after the first or second dose of rotavirus vaccination in some populations (Mexico and Brazil) but not in others (US).^21,26 The low-level risks of intussusception identified in Mexico and Brazil are substantially lower than the risk identified with the first rotavirus vaccine, RotaShield^®, which was withdrawn from the market in 1999. RotaShield^® posed a risk of intussusception in approximately 1 per 10,000 vaccinated infants. In Brazil and Mexico, the risk of intussusception is approximately 1 to 2 per 100,000 vaccinated infants.

The World Health Organization (WHO) Global Advisory Committee on Vaccine Safety (GACVS) reviewed the data from Mexico and Brazil and concluded that the benefit of rotavirus vaccination greatly outweighs any potential risk of intussusception.^23,24 WHO reaffirmed its recommendation for global use of rotavirus vaccines after reviewing the evidence.

Why do a small number of infants develop intussusception after rotavirus vaccination, while most infants who get vaccinated do not?

In most cases, the reasons infants develop intussusception are not known.

Were studies conducted to assess the safety of Rotarix^® and RotaTeq^® rotavirus vaccines before introduction?

The risk of intussusception for Rotarix^® and RotaTeq^® had been assessed in large clinical trials prior to licensure in the US, Finland, and Latin America. Each trial involved more than 70,000 participants and no increased risk for intussusception was observed. Researchers found that the risk of intussusception was similar among children who received the vaccine and those who received a placebo, indicating that the currently available vaccines are safe for use.^13,15

Have additional studies to assess safety been conducted following vaccine introduction?

Yes. A study was conducted in Mexico and Brazil was to assess whether vaccination with Rotarix^® was associated with an elevated risk of intussusception. The study identified a possible low-level risk of intussusception.²¹ In Mexico, Rotarix^® was associated with a slightly increased risk of intussusception in the week following the first dose of vaccine (approximately 1 per 51,000 vaccinated infants). In Brazil, a risk was not seen after the first dose, but a possible risk was noted the week following the second dose (approximately 1 per 68,000 vaccinated infants).

An Australian study found a slightly increased risk of intussusception in the week after receipt of the first dose of Rotarix^® and RotaTeq^® but no increase in the overall rates (cases expected vs. cases observed) of intussusception in infants aged 1 to 9 months.²⁵ Additionally, a study of US infants found no increased risk of intussusception associated with RotaTeq^® following the administration of nearly 800,000 doses of the vaccine.²⁶ These findings further contribute to the growing body of evidence that the benefits of rotavirus vaccination far exceed any low-levels risks associated with the vaccine.

How do the rates of intussusception in RotaShield^®, (withdrawn from market in 1999) compare the rates of intussusception found with the newer vaccines?

The low-level risks of intussusception observed with the currently licensed vaccines are substantially lower than the risk identified with the first rotavirus vaccine, RotaShield^®, which was withdrawn from the market. For example, RotaShield^® posed a risk of intussusception in approximately 1 per 10,000 vaccinated infants. In recent studies conducted in Brazil and Mexico, the risk of intussusception was approximately 1-2 per 100,000 vaccinated infants, and in a study conducted among US infants, no increased risk was observed.^21,26

Why are WHO, FDA, CDC, and rotavirus vaccine manufacturers monitoring rotavirus vaccines so closely for intussusception?

Intussusception was found to be a side effect of the first rotavirus vaccine (RotaShield^®). As a result, that vaccine was voluntarily withdrawn from the market by the manufacturer. The possibility of a small increase risk for intussusception has been observed with newer rotavirus vaccines (Rotarix^® and RotaTeq^®) in some populations (Mexico and Brazil) but not others (United States).^21,26 However, the documented benefits of rotavirus vaccination against rotavirus are substantial and the WHO reaffirmed its recommendation for global use of rotavirus vaccines after reviewing all of the available evidence.^23,24

Where can I find more information on intussusception?

More information on intussusception is available from:
• US Centers for Disease Control (CDC): Statement Regarding Rotarix^® and RotaTeq^® Rotavirus Vaccines and Intussusception.²⁷
• US Food and Drug Administration (FDA): RotaTeq (Rotavirus Vaccine) and Intussusception Information²⁸ and Information on Rotarix- Labeling Revision Pertaining to Intussusception.²⁹
• World Health Organization (WHO): Rotavirus Vaccine and Intussusception (GACVS report December 2010)²³ and Rotavirus Vaccines and Intussusception (GACVS report December 2011)²⁴

Do rotavirus vaccines contain a pig virus (porcine circovirus)?

In March 2010, DNA fragments of porcine circovirus—which is common in pork products—was found in both licensed rotavirus vaccines. Porcine circovirus is not known to cause illness in humans or pose any safety risk. The US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) concluded that there is no evidence of a public health risk.^30,31 WHO GACVS reviewed the safety data from clinical trials and spontaneous reports, and concurred with the FDA and EMA, finding that all data supported the continued safety of the vaccine and that the benefits of vaccination far outweighed any currently known risk associated with use of rotavirus vaccines.³²

Is there a safety risk associated with the porcine circovirus that has been found in rotavirus vaccines?

Traces of porcine circovirus—which is common in pork products—were found in rotavirus vaccines. Porcine circovirus is not known to cause illness in humans or pose any safety risk. The US Food and Drug Administration and European Medicines Agency determined that the proven benefits of rotavirus vaccines outweigh any theoretical risks.^30,31 WHO reviewed the safety data from clinical trials and spontaneous reports and found that all data supported the continued safety of the vaccine and considered that the benefits of vaccination far outweighed any currently known risk associated with use of rotavirus vaccines.³²

Where can I find more information on porcine circovirus?

More information on porcine circovirus is available from:
• US Food and Drug Administration: Information for Parents and Caregivers.³⁰
• World Health Organization: Porcine circoviruses and rotavirus vaccines.³³

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References

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22. Patel MM, Steele D, Gentsch JR, Wecker J, Glass RI, Parashar UD. Real-world impact of rotavirus vaccination. Pediatric Infectious Diseases Journal. 2011;30(1 Suppl):S1–S5. Available at: http://journals.lww.com/pidj/Fulltext/2011/01001/Real_world_Impact_of_Rotavirus_Vaccination.1.aspx. Accessed on 31 August 2012.
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26. Shui I, Baggs J, Patel M, et al. Risk of intussusception following administration of a pentavalent rotavirus vaccine in US infants. Journal of the American Medical Association. 2012;307(6):598–604. Available at: http://jama.ama-assn.org/content/307/6/598.short. Accessed on 31 August 2012.
27. Statement Regarding Rotarix® and RotaTeq® Rotavirus Vaccines and Intussusception page. CDC website. Last modified November 3, 2010. Available at: www.cdc.gov/vaccines/vpd-vac/rotavirus/intussusception-studies-acip.htm. Accessed on 29 August 2012.
28. RotaTeq (Rotavirus Vaccine) and Intussusception Information page. FDA website. Last updated April 30, 2009. Available at: www.fda.gov/BiologicsBloodVaccines/Vaccines/QuestionsaboutVaccines/ucm100895.htm. Accessed on 29 August 2012.
29. Information on Rotarix – Labeling Revision Pertaining to Intussusception page. FDA website. Last updated September 22, 2010. Available at: www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm226690.htm. Accessed on 29 Aug 2012.
30. Information for Parents and Caregivers page. FDA website. Last updated May 14, 2010. Available at: www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm205547.htm. Accessed on 29 Aug 2012.
31. European Medicines Agency confirms positive benefit-risk balance of Rotarix: Porcine circovirus type 1 in the oral vaccine poses no risk to public health [Press release]. London: European Medicines Agency; July 22, 2010. Available at: www.ema.europa.eu/ema/index.jsp?curl=pages/news_and_events/news/2010/07/news_detail_001059.jsp&mid=WC0b01ac058004d5c1. Accessed on 29 Aug 2012.
32. Finding of DNA fragments of porcine circoviruses in rotavirus vaccines page, World Health Organization website. Last updated June 4, 2010. Available at: www.who.int/immunization_standards/vaccine_quality/rotavirus_pcv1/en/index.html. Accessed 29 Aug 2012.
33. Porcine circoviruses and rotavirus vaccines page [2010 GACVS meeting]. WHO website. Available at: www.who.int/vaccine_safety/topics/rotavirus/rotarix_and_rotateq/Jun_2010/en/. Accessed 29 Aug 2012.

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