Coronavirus disease (COVID-19) vaccines Q&A

21 June 2021 - This page will be regularly updated.

COVID-19 vaccines protect you from severe illness and death from the virus by helping the body develop immunity. They may also help reduce the spread of the virus between people, so one person’s choice to get vaccinated could save many more lives.

COVID-19 vaccines are a key tool in ending the pandemic and getting societies back to normal. Mass vaccination campaigns should also help reduce the pressure on health workers and hospitals, allowing them to attend to patients with other conditions.

WHO recommends you get a COVID-19 vaccine as soon as one is available to you.

Yes. There are strict protections in place to help ensure the safety of all COVID-19 vaccines. 

Before receiving authorization from WHO and national regulatory agencies, COVID-19 vaccines undergo rigorous testing in clinical trials to prove that they meet internationally agreed standards for safety and efficacy.

The Oxford-AstraZeneca, Pfizer-BionTech, Moderna, Johnson and Johnson, Sinopharm and Sinovac vaccines have been approved for use by WHO. These vaccines have been tried, tested and proven to be safe. Over two billion COVID-19 vaccine doses have been administered globally and millions of people have been vaccinated in Africa. 

As with all vaccines, WHO and regulatory authorities continuously monitor their use to confirm that they remain safe for all who receive them.

More information on COVID-19 vaccine safety can be found here

Like any vaccine, COVID-19 vaccines can cause side effects, although many people do not experience them. 

The vast majority of side-effects are mild and short-lived. They can include pain where you received the injection, tiredness, fever, chills, nausea or a headache.

Severe events after vaccination are extremely rare. If side effects worsen or don’t go away after a few days, contact your healthcare provider. 

COVID-19 vaccines are proven to significantly reduce the risk of severe illness and death from the virus. 

Yes. Data from clinical trials and real life settings is showing that COVID-19 vaccines authorised for use are highly effective in protecting against severe illness and death from COVID-19. 

Ensuring the safety and quality of all vaccines is one of WHO’s highest priorities and WHO works closely with national authorities to ensure that global norms and standards are developed and implemented to assess the quality, safety and efficacy of vaccines. 

Increasing amounts of data suggest that most vaccines provide a level of protection against all variants, especially protecting against severe disease and death. However, early data from a number of countries shows that protection against the Beta and Delta variants may be lower than against the original virus strain, especially after one dose of a two-dose vaccine, yet more research is needed for a definitive answer.

WHO recommends that those most at risk of severe illness, death and exposure to COVID-19 get vaccinated first.
These include frontline health workers (especially those providing COVID-19 patient care), older people and those living with other diseases, or existing conditions including hypertension, diabetes, cardiovascular disease, HIV or cancer.

COVID-19 vaccines save lives. When you get the call, get the vaccine.

It usually takes a few weeks after vaccination for the body to develop immunity, so it is possible that you could be infected just before or just after vaccination and then get sick because the vaccine did not have enough time to provide protection.

People should continue using proven safety measures like regular hand-cleaning, using masks and practicing social distancing to reduce transmission of the virus.

Yes. If you are a young adult you are not at the highest risk of severe illness or dying, but you are still at risk.

Some vaccines are not yet recommended for those younger than 18 years old since they have not yet been tested in this age group. Once vaccines are approved and recommended for use in this age group, you should follow the national recommendations.

COVID-19 vaccines are effective in preventing severe disease and death, yet because these vaccines have only been developed in recent months it is still too early to know the exact duration of the protection they provide.

Research is ongoing to answer this question. However, it’s encouraging that the available data suggests that most people who recover from COVID-19 develop an immune response that provides protection against reinfection for some time, although we’re still learning how strong this protection is, and how long it lasts.

Check with your national health authorities or a local healthcare provider:

  • if the vaccine is available to you;
  • when it will be your turn to get the vaccine;
  • where and how to get your COVID-19 vaccine; and,
  • whether you need to register for it.

It's not recommended to take over the counter medicines, like ibuprofen or antihistamine immediately before getting vaccinated.

On the day of your vaccination make sure you give yourself enough time to complete all the steps required, including being monitored after vaccination on site for at least 20 minutes.

Pregnant women should get vaccinated when benefits outweigh the risks.

We do not have enough data on the safety of vaccines for pregnant women. However, data from the United States, where around 90 000 pregnant women have been vaccinated with messenger RNA (Mrna) vaccines like the Pfizer-BionTech and Modena vaccines have not raised any safety concerns.

  Countries have different guidelines based on their own situations. In countries where pregnant women can choose to get the vaccine, health workers should help them to understand the risks and benefits so they can make an informed decision.

If you are unsure, please ask your doctor.

There is no evidence that COVID-19 vaccines affect the menstrual cycle, but this has not been studied in detail yet. 

Some women have claimed that after taking the vaccine their periods have either become heavier, lighter, or the duration of the period changed. We don't know yet if the vaccine is causing these changes, but there are several reasons why the menstrual cycle could change, including changes in diet, weight or exercise routines. 

COVID-19 vaccines will not affect your ability to get pregnant, even if there are some temporary changes in your menstrual cycle. If you are on fertility treatment, let a health professional know exactly what treatment you are on before you get the COVID-19 vaccine.

If there are any changes to your menstrual cycle, they should be temporary and harmless. Yet if you are worried, please contact a health professional. 

For two-dose vaccines, the interval between doses depends on which vaccine you get and the guidelines from the government in your country. 

For the Oxford-AstraZeneca vaccines, longer intervals between doses between eight to twelve weeks give greater protection. For the Pfizer-BionTech, Moderna and Sinopharm vaccines, you should ideally get your second dose between three to four weeks after your first dose. 

Even a single dose of a two-dose vaccine should provide some protection from the virus, so if you get the chance please get the vaccine. 

Clinical trials are looking at whether you can have a first dose from one vaccine and a second dose from a different vaccine. 

There isn't enough data yet to recommend this type of combination. 

It takes time for your body to build protection after vaccination. COVID-19 vaccines that require two shots may not fully protect you until about two weeks after your second shot. COVID-19 vaccines that require one shot take around two weeks for your body to build immunity. 

If you experience side effects from the vaccine, to reduce pain and discomfort where you got the shot, apply a clean, cool and wet cloth to the area. You can also use or exercise your arm. To reduce any discomfort from fever, drink plenty of fluids and dress lightly.

For COVID-19 vaccines that require two injections, side effects from the second shot may be greater than after the first. This shows that your body is building protection and should go away within a few days. If side effects worsen or don’t go away after a few days, contact your healthcare provider. Severe events after vaccination are extremely rare. 

There is no evidence that having a drink or two can render any of the current COVID-19 vaccines less effective, so if you drink alcohol in moderation it should not be a problem. Yet heavy alcohol consumption, particularly over the long term, can suppress the immune system. 

If you have a fever after getting the vaccine or have some pain where you received the injection you can take widely available painkillers such as Paracetamol or Tylenol. 

For the first fourteen days after getting a vaccination, you do not have significant levels of protection, and then it increases gradually. For a single dose vaccine, immunity will generally occur two weeks after vaccination. For two-dose vaccines, both doses are needed to achieve the highest level of immunity possible. Vaccination protects you from getting seriously ill and dying from COVID-19, however, no vaccine is 100% effective. 

We are still learning about the extent to which the vaccines will stop you from being infected and passing the virus on to others. Current evidence shows that vaccines provide some protection from infection and transmission, but it is less than against serious illness and death. We are also still learning about protection against variants of concern. For these reasons, and while many of those in the community may not yet be vaccinated, maintaining other prevention measures is important, especially in communities where SARS CoV-2 circulation is significant. 

To help keep you and others safe, and while efforts continue to reduce transmission and ramp up vaccinations, you should continue to maintain at least a 1-metre distance from others, cover a cough or sneeze in your elbow, clean your hands frequently and wear a mask, particularly in enclosed, crowded or poorly ventilated spaces.

Always follow guidance from local authorities based on the situation and risk where you live.

Yes. Of course, it will depend on which vaccines your country receives, but as more vaccines are approved, there will be multiple safe and effective COVID-19 vaccines for countries to choose from.

The COVAX facility – which is a global initiative to ensure equitable access to COVID-19 vaccines for up to 20% of people in African countries – only distributes vaccines that have received WHO's Emergency Use Listing (EUL). 

EUL is the WHO gold standard to confirm the quality, safety and efficacy of vaccines used in  public health emergencies. It also allows countries to speed up regulatory approval and import the vaccine. 

The Oxford-AstraZeneca, Pfizer-BionTech, Moderna, Johnson and Johnson, Sinopharm and Sinovac vaccines have all received EUL from WHO. Other vaccines are also under review.

As more vaccines are approved, there will be multiple safe and effective COVID-19 vaccines for countries to choose from.

Scientists around the world are developing many potential vaccines for COVID-19. These vaccines are all designed to teach the body’s immune system to safely recognize and block the virus that causes COVID-19.

Several different types of potential vaccines for COVID-19 are in development, including:

  • Inactivated or weakened virus vaccines, which use a form of the virus that has been inactivated or weakened so it doesn’t cause disease, but still generates an immune response.
  • Protein-based vaccines, which use harmless fragments of proteins or protein shells that mimic the COVID-19 virus to safely generate an immune response.
  • Viral vector vaccines, which use a safe virus that cannot cause disease but serves as a platform to produce coronavirus proteins to generate an immune response.
  • RNA and DNA vaccines, a cutting-edge approach that uses genetically engineered RNA or DNA to generate a protein that itself safely prompts an immune response.

For more information about all COVID-19 vaccines in development, see this WHO publication, which is being updated regularly.

All the vaccines that have achieved WHO Emergency Use Listing are highly effective in preventing severe disease and death due to COVID-19.

It is not possible to compare the efficacy estimates of different vaccines due to the different approaches taken in designing their respective studies, and the prevalent variants of the virus circulating at the time of the study. 

Take whichever WHO-approved vaccine that is made available to you. It is important to be vaccinated as soon as possible. 

The expiry date of vaccines is based on the period for which there is evidence that they retain their potency, so vaccines that have passed their expiry date may not protect you against the virus. Expiry dates are not determined based on safety considerations.

Expired vaccines should not be used. 

Expired vaccines should not be used. They should be disposed of in accordance with national guidelines.

Yes. Senegal, South Africa, Egypt, Tunisia and Morocco are the only African countries with some vaccine manufacturing capacity.

For more African countries to develop these capabilities, we need more international cooperation and greater sharing of expertise.

With flexibility around technology transfer and the waiving of intellectual property rights during the pandemic, investment in African countries could start by focusing on filling and packaging COVID-19 vaccines. From this, further investment could help build up more complex capacities for manufacturing and research and development.

More detailed information on vaccine manufacturing capacity in Africa can be found here.

Vaccine development and clinical trials are a key research priority for COVID-19 in Africa. Voluntary clinical trials for COVID-19 vaccines have taken place in Kenya and South Africa. Testing vaccines in Africa ensures that data is generated on the safety and efficacy of promising vaccines for the African population. 

These are not the first vaccines to be tested in Africa, with vaccines like the conjugate meningitis A and Ebola vaccines being tested on the continent before rollout.  

All clinical trials for COVID-19 vaccines are voluntary. Hundreds of thousands of people have been involved in clinical trials around the world, which has provided crucial data to help make sure that COVID-19 vaccines work.

No, clinical trials for COVID-19 vaccines have not been rushed.

Given the urgent need for COVID-19 vaccines, unprecedented investment and scientific collaboration is changing how vaccines are developed. Some steps in the research and development process for COVID-19 vaccines have taken place in parallel, while still maintaining strict clinical and safety standards. For example, some clinical trials are evaluating multiple vaccines at the same time, but this does not make the studies any less rigorous than normal.

From your Ministry of Health, other official health authorities in your country or your local healthcare professional.