COVID-19 vaccines: the latest developments
A summary of the latest announcements, research and reaction from the European Respiratory Society President
In the last few weeks, we have seen several encouraging announcements from companies working to develop vaccines to protect against COVID-19.
Which vaccines have demonstrated successful results so far?
- Pfizer/BioNtech vaccine has been shown to have an efficacy (how well a drug works under controlled and best-case conditions, such as in a trial) of 90%. It was tested on 43,000 people, with no safety concerns reported. Read the Pfizer and BioTech press release.
- Moderna reported that their vaccine has an efficacy of 94.5%. They tested it in a trial involving 30,000 people. Half of them received the vaccine and half received a placebo (not medicine) injection. No significant safety concerns were reported. Read the Moderna study overview.
- The Oxford University/AstraZeneca vaccine studies have shown a combined efficacy of 70%, this is from several different trials. One trial demonstrated 62% efficacy, and another in which the recipients received a half dose, followed by a full dose, showed 90% efficacy. Further research into the optimal dose will continue. In an earlier trial looking at the immune reaction from the vaccine, a high proportion of people developed antibodies including older individuals. Read the published data in Lancet.
What has been the reaction from leading respiratory experts?
President of the European Respiratory Society (ERS), Professor Anita Simonds, said: “These announcements are very encouraging in the fight against COVID-19 and ERS reiterates its support for the development of safe and effective vaccines that can prevent and protect against SARS-CoV-2 (the virus that causes COVID-19). Vaccines will play a very important role in controlling this virus alongside measures that are currently recommended to slow the spread, such as frequent hand washing, wearing a face covering and physical distancing.
She added: “Both efficacy and safety are important. For example, an efficacy of 50% means that there was a 50% reduction in the number of cases of symptomatic COVID-19 disease in people who received the vaccine, compared to those who did not. In other words, among those vaccinated half the people who would have got symptomatic disease did not get it. In fact, a vaccine with 50% efficacy or higher is usually accepted as highly effective by the regulators. But head to head comparisons of efficacy are not everything. We need to take into account whether severe cases were reduced, and also whether the vaccine can reduce transmission. It is also possible that some vaccines may work better in different groups of people such as the elderly, and those with other health conditions.
Safety has been extensively investigated, and no risks have been seen in the 6-week period of follow-up in the large trials. Further follow-up is important once the vaccines are rolled out, as any long-term effects can only be detected that way.
“There are now around 50 ongoing COVID vaccine trials, 12 of which are at the phase 3 stage and are undergoing large-scale efficacy tests, so we are likely to see more reports like this in the coming months. We are all hopeful for a return to a more normal existence as the pandemic has been a very challenging time for everyone, but it is important to keep the reports in perspective, as they are based on announcements of interim analyses only.
“While there are some unanswered questions about these vaccines at present, it is impressive how rapidly scientists have worked to develop these potentially life-saving treatments. The ERS and all those interested in healthcare have an important role to play in disseminating accurate information on the vaccines to help develop ‘vaccine confidence’ in both the general public and patients”.
What steps are still needed?
Any vaccine that is found to be successful in a trial must also be approved for use by regulatory bodies. In the European Union, the European Medicines Agency (EMA) will review all potential vaccines to look at how effective and how safe they are. They must approve any vaccine before it can be offered to the general population. Find out more about how the EMA approves vaccines.
The UK regulating body, Medicines and Healthcare products Regulatory Agency (MHRA), approved the Pfizer/BioNtech vaccine on 2 December and the roll-out to the public began on 8 December. Other countries are suspected to announce their decisions in the coming weeks.
Rolling out a vaccine across the population will be difficult to organise. Vaccines must be developed and distributed on a huge scale to protect populations across the world. Some of these vaccines also need to be stored at very cold temperatures; this can be a problem for healthcare centres who will offer the vaccinations.
Who will receive the vaccine once approved?
If any vaccine is approved, it will be up to each country to decide who to give the vaccine to first.
The most likely people to receive the vaccine first will be from vulnerable groups, such as:
- elderly people (especially those living in care homes),
- people with pre-existing conditions, including certain lung conditions, and
- healthcare workers, as they come into contact with vulnerable people.