Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said on Friday that chances of a coronavirus vaccine being very effective (one that provides 98 percent protection) are slim.
During a question and answers session with the Brown University of Public Health, the leading infectious disease expert in the country said that scientists are trying for a coronavirus vaccine that is at least 75 percent effective. He added that a vaccine that is even 50 or 60 percent effective will be acceptable as well.
Watch live as @ashishkjha of @brown_sph discusses the challenges facing public health leaders during the coronavirus pandemic with one of the nation’s most visible public health leaders, Dr. Anthony J. Fauci. https://t.co/G4yC38tFdj
— Brown University (@BrownUniversity) August 7, 2020
Fauci explained that the chance that a vaccine is highly effective are ‘not great’, and this means that the public health approach should not be abandoned. That approach comprises of practicing safety measures, wearing masks, keeping your distance, and washing your hands regularly.
He further explained that a vaccine will get help get this pandemic under control, but it is unlikely that it will get rid of the disease altogether.
The Food and Drug Administration has also announced that any vaccine that is safe and at least 50 percent effective against coronavirus will be authorized by the agency.
The FDA commissioner, Dr. Stephen Hahn, also said last month that though the vaccines should ideally be more than 50 percent effective, in case of a coronavirus vaccine the country might just end up with a vaccine that reduces a person’s risk of a Covid-19 infection on average by just 50%.
FDA says it would clear a coronavirus vaccine so long as it's safe and at least 50% effective https://t.co/TiYnOaCkAw
— CNBC (@CNBC) July 30, 2020
This means that a vaccine would be just like the influenza vaccines that provide lower immunity from disease and not like the measles vaccine that is 93 percent effective, according to the Centers for Disease Control and Prevention.
Right now, drug companies like Pfizer, Moderna, and Oxford University have begun the phase 3 trials of their respective vaccine candidates that will enroll nearly 30,000 subjects each. The health experts will be able to make an assessment about the vaccine effectiveness and safety by December or early next year, once the results of these trials start coming in.
We just announced that the Phase 3 study of mRNA-1273, our vaccine candidate against COVID-19 has begun. The Phase 3 study being conducted in collaboration with @NIH and @BARDA. Read more here: https://t.co/Xi9SV6fk4z pic.twitter.com/oESeuKjF08
— Moderna (@moderna_tx) July 27, 2020
With the promise of a vaccine by January #operationwaspspeed, we're all wondering what a vaccine will be like. Moderna enters Phase 3 trials, Pfizer & Oxford Phase 2, but federal guidelines – issued four weeks ago – give us the best indication. @latimesscience
— Thomas Curwen (@tcurwen) July 30, 2020
Previously, the director has also said that he is worried that the vaccine might not provide long term immunity. In that case people may have to get booster shots each year or after a fixed amount of time.
People are expecting that the life will return to normal once the vaccine comes, but World Health Organization Director-General Tedros Adhanom Ghebreyesus said just the previous week that there might never be a “silver bullet” for the virus, which continues to rapidly spread worldwide.
WHO Director-General Dr. Tedros on potential COVID-19 vaccines: “There is no silver bullet at the moment and there might never be.” pic.twitter.com/eqdjoY7zJa
— The Recount (@therecount) August 3, 2020
WHO experts have also warned that even after the conclusion of the phase three trials underway, the vaccine might not be available for some time.
Mike Ryan, executive director of the WHO’s emergencies health program in virtual panel said, “Phase three means this is the first time this vaccine has been put into the general population into otherwise healthy individuals to see if the vaccine will protect them against natural infection.” He added that it does not mean that we are nearly there.
Vaccines seem like an easy enough thing to make, but in fact are very complex in practice. The best vaccine for any disease is safe, very effective at preventing an infection, and even prevent the spread of the pathogen in the population. However, not many vaccines can do all three jobs.
Even after 30 years of isolating HIV which causes AIDS, scientists have not been able to make a vaccine that can prevent an infection.
Even for dengue that was first discovered in 1943, a vaccine was just approved last years. That vaccine also raised concerns that it can make infection worse for some people. The fastest vaccine till date was approved for mumps which took four years.
Dengue vaccine is a good example of why should not do this.
— Fernando (@1908_fernando) August 2, 2020
Dengue Vaccine Controversy In The Philippines https://t.co/NVPPqQaM0R
— Ron Claussen Tees (@RonsTees) July 31, 2020
The scientists also have to make sure that the vaccine is safe. Previously when the scientists looked for a vaccine for SARS, they developed one that cause hepatitis in ferrets.
Another issue is the “antibody-induced enhancement” where antibodies produced in reaction to the vaccine make future infection seven worse, just like the dengue vaccine in some cases.
However, scientists working on coronavirus vaccine have some previous data to go on.
Before the novel coronavirus, two other coronaviruses caused outbreaks that killed thousands. These were SARS and MERS. There have been plenty of research conducted on both which can help scientists understand what they need to do, in order to develop this new vaccine.