Coronavirus vaccines & BCG

Does the BCG vaccine provide protection against the coronavirus disease?

There is no evidence that the BCG vaccine protects people against infection with the coronavirus that causes the disease covid-19.

A coronavirus causes the disease Covid-19

A coronavirus causes the disease Covid-19

Some trials are now underway to provide a clear answer to this question. The World Health Organisation (WHO) does not currently recommend people have BCG in order to try and prevent infection with coronavirus.1

Are there any vaccines that provide protection against coronavirus disease?

There are currently two vaccines that have been through clinical trials and which have been found to be effective. However, neither have been yet authorised for use.

The first vaccine may be available late in 2020 or early in 2021

How is a vaccine tested?

There are several stages or clinical trials involved in testing any vaccine. The early stages are to find out if the vaccine is basically safe and if there are any serious short term side effects. It is also important to find out what dose is best.

None of these trials help to find out if the vaccine actually works. This is usually done by signing up several thousand volunteers to take part in a trial. Then half the volunteers are given the vaccine and half are given a dummy injection that does not contain the vaccine. This is known as a placebo. Nobody except some independent researchers know who has the real vaccine and who has the placebo.

It is then necessary to wait untill a number of people become infected. The documents can then be looked at to find out if the people who have been infected had the vaccine or the placebo. This then tells the researchers whether the vaccine is working.

The need to carefully carry out these trials is a major reason why the devlopment of any vaccine takes a long time.

Why is it not possible to inject volunteers with the virus after they have been given the trial vaccine?

This would speed up the development of a vaccine. It is known as a human challenge study. But it is controversial, because injecting a volunteer with the virus might result in them becoming seriously ill if the vaccine doesn't work.2Dr Michael Mosley, Daily Mail, Saturday October 24th 2020,

Why isn't there a new vaccine for TB?

This is probably because not enough money has been made available despite the large number of deaths from TB each year. One benefit from coronavirus might be that more attention is given to developing a new vaccine for TB.

There is more about the BCG vaccine and also the development of BCG.

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This page was last updated in November 2020.
Author Annabel Kanabus

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