There are more than 130 potential coronavirus (COVID-19) vaccines currently being worked on by researchers around the world. Of those, 19 are being tested in humans.
After some encouraging initial results, researchers remain cautiously optimistic that a safe and effectively vaccine can be made. Some of the biggest questions will be answered in the next few weeks as large-scale human trials roll out around the globe.
About 8,000 people in the UK have now received the vaccine developed by the University of Oxford.
Phase three trials are also taking place in Brazil, where 4,000 people will be vaccinated, and in South Africa, there 2,000 volunteers began lining up for the shot.
Oxford was already working on a vaccine for a different coronavirus when the pandemic hit, giving researchers a head start on testing this one.
“This is the first study that has been done on the African continent, but in all likelihood, it will be the first of at least three to four other vaccine studies on COVID-19 -- different vaccines,” said Shabir Madhi, a professor of vaccinology at Wits University.
In the UK, volunteers are also testing a vaccine developed by the Imperial College of London. This stage will include 300 people with a 6,000-person trial planned for October.
In the United States, the vaccine created by the biotech company Moderna is entering phase three trials with plans to test it in at least 1,000 people in Chicago, starting this month.
At least 4,000 participants will be over age 65. Researchers also want to include many African-American and Hispanic volunteers.
“I don’t think it will be that hard to find people interested,” said Dr. Richard Novak, the University of Illinois at Chicago head of infections diseases.
Pfizer and its German biotech partner, Biontech, just announced results from phase one and two trials. All 24 volunteers given two doses of the vaccine developed higher levels of antibodies than typically seen in recovered patients.
More than half reported non-serious side effects, such as fever and sleep disruption.
“After the second dose, I felt a little bit achey and my temperature was elevated, and so I took a Tylonol and felt better,” one patient said.
Researchers in Australia, India and Europe are also testing a tuberculosis vaccine developed in the early 1900s to see if it might offer some partial protection against COVID-19.
The groups being tested right now don’t include pregnant women and children, but obviously researchers will need to make sure the vaccine is safe for them, too.
Once a vaccine is proven safe and effective in the initial study participants, the researchers will then go back and redo the first stages of the trials and include pregnant women, children and people with more health problems. It will be tested in volunteers from those groups before it ever becomes widely available.