WHO responds to questions raised regarding the vaccine report in China Q1: What’s the difference between Category 1 and 2 vaccines in China?Category 1 vaccines are vaccines in the government’s Expanded Program on Immunization that are used to protect children from 12 infectious diseases. Category 1 vaccines are provided free for all children in China, and it is mandatory in China for children to be vaccinated with these vaccines. Category 2 vaccines are additional vaccines that parents may choose to have for their children – and help protect against diseases such as Haemophilus influenza type b disease, invasive pneumococcal disease, and rotavirus gastroenteritis. Category 2 vaccines are not provided for free in China. Q2: Who makes sure that Category 1 and Category 2 vaccines are safe? WHO has confidence in the manufacturing and licensing of vaccines in China – both for Category 1 and Category 2 vaccines. The China National Regulatory Authorities for vaccines (CFDA and NHFPC) have been assessed in 2010 and 2014 by WHO and found to meet all international regulatory standards, including assuring use of current Good Manufacturing Practices. The issue in the current situation relates to storage and distribution of vaccines. Category 1 vaccines are distributed through the government’s CDC system, from manufacturer to clinic. This Controlled Temperature Chain has been evaluated by WHO and UNICEF and found to be of high quality. However, Category 2 vaccines are not distributed through the same system. Q3: Does ‘no toxic reaction’ mean no harm? “No toxic reaction” means that the child is extremely unlikely to get sick as a result of receiving the expired or improperly stored vaccine. However, if the vaccine had lost potency due to expiration or improper handling, the child could be harmed if he or she gets infected later in life because the impotent vaccine provided no protection from the disease for which the vaccine was intended. This situation would be the same as if the child had never received the vaccine. Q4: If my child has been vaccinated with an ineffective vaccine, does he or she need to be re-vaccinated with an effective one?In general, because administering an expired or improperly handled may not provide protection from the disease for which the vaccine was intended, the vaccination should be repeated. It is safe to repeat the vaccination, and these can be given either immediately for inactivated vaccines or after 28 days for live virus vaccines. However, the risk of different vaccine preventable diseases varies by age, so not all vaccinations need to be repeated. There are some diseases for which a child’s immunity and need for revaccination can be determined with a blood test, for example measles, rubella, hepatitis A, hepatitis B, and varicella. Decisions to revaccinate should made in consultation with health professionals in the EPI clinic. Q5: What does “minimal safety risk” really mean?As far as we know, vaccines that are stored out of their required storage temperature range or that have passed their expiration date do not become contaminated or toxic; rather, the issue is that they cannot be guaranteed to be potent. All vaccines carry some risk of side effects such as an allergic reaction to a component of a vaccine. However, administering an expired or improperly stored vaccine should not pose any additional risk or toxic reaction beyond the normal risk of side effect. Q6: If a child is vaccinated with ineffective vaccines, will this result in any harmful outcomes?A child being administered an improperly stored vaccine is extremely unlikely to get sick as a result of receiving the vaccine. However, if the vaccine had lost potency due to expiration or improper handling, the child could be harmed if he or she gets infected later in life because the impotent vaccine provided no protection from the disease for which the vaccine was intended. This situation would be the same as if the child had never received the vaccine. Q7: Should we have our kids vaccinated?Yes. Children in China, as children in the rest of the world, need vaccines to protect them from vaccine preventable diseases. The Chinese immunization program protects children from 12 infectious diseases. All children, except for the very small number of children who cannot be vaccinated due to a medical reason, should be vaccinated with vaccines used in the routine program. Vaccination is the safest way to protect children from vaccine preventable diseases. We will answer more questions tomorrow.