Top Three Covid-19 Vaccines Under Development To Show Strong Results
As three competing laboratories announced promising results from early trials in humans, the race for a vaccine against the coronavirus intensified on Monday.
Now comes the crucial part of developing a vaccine; to prove the vaccine protects against the virus and induce immunity for long enough.
Dr. Peter Jay Hotez, a vaccine researcher at the Baylor College of Medicine said each of these vaccines that showed promising results in human trials is worth taking all the way through to a phase three study. Phase three trials will test the efficiency of the vaccine.
Recently early results of the human trials were published by two vaccine developers in The Lancet; vaccine by a Chinese company CanSino Biologics and another by Oxford University in partnership with British-Swedish drugmaker AstraZeneca.
The drug giant Pfizer in collaboration with German company BioNTech, shared their results online. The biotech company Moderna used similar technology to Pfizer to develop its vaccine, and the early results were published last week.
All the vaccines produced strong immune responses in people who received the vaccine and had only minor side effects; the developers released results on Monday.
Professor Stacey Schultz-Cherry of the St. Jude Children’s Research Hospital said all the vaccines look good, and more than one vaccine would be necessary to combat the virus globally.
All the developers claimed that their vaccines induced antibody levels comparable to those who recovered from COVID-19. But they noted that matching immune responses to convalescing patients do not necessarily guarantee any degree of immunity. It does not really predict if the vaccine is going to work against COVID-19 infections.
All the developers pointed out that the immunity induced by the vaccines is likely to require a second dose to enhance its dose.
Among the many vaccines under development, the one developed by the partnership between Oxford and AstraZeneca may be the most closely watched vaccine.
Even before the vaccines have proven effective, the Britan, the United States, and many other nonprofit and government groups have already signed deals of millions of dollars for a total of 2 billion doses of vaccine. The US and British officials believe that Russians are spying on the Oxford research, which developed the first vaccine to enter the last phase of the trial.
The Oxford vaccine has already given to 10,000 participants in Brazil, South Africa, and Britain. Along with the testing of the Moderna vaccine, the US is going to test the Oxford vaccine in 30,000 participants, beginning next week.
The results published by the Oxford scientists on Monday reported that among the few hundred participants who received the vaccine, ten people who got the booster shot showed the most promising results.
Based on the early results available so far, the CanSino vaccine from china, which was tested in 500 people, is least likely to be effective. Compared to other vaccine candidates, this one was pretty weak. However, both the CanSino and oxford vaccines use the same technology of altering genes of another common virus to make them mimic the coronavirus.
The Oxford scientists use an adenovirus found in chimps, which would be new to the human body. But the CanSino vaccine, on the other hand, makes use of a common cold virus in humans, against which few people have preexisting antibodies. This could prevent from getting the desired results.
The COVID -19 vaccine by Pfizer-BioNTech partnership was tested in 60 participants in Germany initially and demonstrated a strong immune response. They use the same technology as the Moderna vaccine, using specially engineered genetic material, mRNA. The early results of the Pfizer vaccine show even stronger immune response.
However, the long term effects of the vaccines are questionable as none of them has been able to measure the results over more than a few weeks.
The eagerness of vaccine developers to promote such inconclusive results may actually undermine more immediate public health efforts to control the virus, like social distancing and wearing masks, argued Hotez.
It seems like miracles are around the corner, which is not the case. It’s going to take years to sort out the situation, he said.