According to SAGE, the Pfizer-BioNTech COVID-19 mRNA vaccine is safe and effective. Nevertheless, there are specific populations for whom vaccination is not recommended, either due to contraindications, lack of supply, or limited data. These populations currently include people with a history of severe allergies, most pregnant women, international travellers who are not part of a prioritized group, and children under 16.
The priority is to start vaccinating health workers at high risk of exposure, followed by older adults, before immunizing the rest of the population.
People with allergies
People with a history of severe allergic reaction to any component of the vaccine should not take it.
Pregnant and breastfeeding women
Pregnant women are at higher risk of severe COVID-19 than non-pregnant women, and COVID-19 has been associated with an increased risk of pre-term birth.
However due to insufficient data, WHO does not recommend the vaccination of pregnant women at this time.
In case a pregnant woman has an unavoidable risk high of exposure (e.g. a health worker), vaccination may be considered in discussion with their healthcare provider.
If a breastfeeding woman is part of a group (e.g. health workers) recommended for vaccination, vaccination can be offered. WHO does not recommend discontinuing breastfeeding after vaccination.
The vaccine has only been tested in children above 16 years of age.
Therefore, at this time, WHO does not recommend vaccination of children below 16 years of age, even if they belong to a high-risk group.
People with known medical conditions
The vaccine has been found to be safe and effective in people with various conditions that are associated with increased risk of severe disease.
This includes hypertension, diabetes, asthma, pulmonary, liver or kidney disease, as well as chronic infections that are stable and controlled.
Further studies are required for the impacts on immune-compromised persons. The interim recommendation is that immune-compromised persons who are part of a group recommended for vaccination may be vaccinated, though when possible, not before receiving information and counselling.
Persons living with HIV are at higher risk of severe COVID-19 disease. Limited safety data exists on HIV-infected persons with well controlled disease from the clinical trials. Known HIV-positive vaccine recipients should be informed, and when possible, counselled in relation to the available data.
People who have or had COVID-19 already
Vaccination can be offered to people who have had COVID-19 in the past.
But given the limited vaccine supply, individuals may wish to defer their own COVID-19 vaccination for up to 6 months from the time of SARS-CoV-2 infection. As more data becomes available on duration of immunity after infection, this time period may be adjusted.
Testing for prior infection is not recommended for the purpose of vaccine decision-making.
At present, WHO does not support the introduction of requirements for proof of vaccination against COVID-19 for international travelers as a condition for exiting or entering a country or for travelling internationally. See WHO’s interim guidance on international travel during the pandemic.
A protective effect starts to develop 12 days after the first dose, but full protection requires two doses which WHO recommends be administered with a 21 to 28-day interval. Additional research is needed to understand longer-term potential protection after a single dose.
Vaccines will not end COVID-19 alone
Safe and effective vaccines will be a gamechanger: but for the foreseeable future we must continue to wear masks, physically distance, avoid crowds and apply other health measures. Being vaccinated doesn’t mean that we can throw caution to the wind and put ourselves and others at risk, particularly because it is still not clear the degree to which the vaccines can protect not only against disease but also against infection and transmission.
What about other vaccines being developed to fight COVID-19
WHO does not usually make vaccine specific recommendations, issuing instead one recommendation that covers all vaccines for a given disease, unless the evidence suggests a different approach is required.
Due to the large variety of COVID-19 vaccines based on very different platform technologies, WHO is looking at vaccines as they are authorized by highly competent national regulatory authorities and that are available in sufficient supply to address the needs of many countries.
WHO has no preferred product, and the variety of products, including their specific attributes and handling requirements, allow for countries to find the products that are most suitable for their circumstances.
WHO’s SAGE is expected to review other vaccines in the coming months.