Possible COVID-19 vaccine in the offing
Dr Evan Shoul, a specialist in infectious diseases, said the announcement had big implications, offering a kernel of hope.
“The results they released were from an early phase of development,” he said. “Vaccines have a whole gestation period, and each stage is a big step towards it being registered. However, each stage also has potential for the vaccine to fail and fall out of the running.”
Professor Gert van Zyl, a virological pathologist at Stellenbosch University, agreed that the announcement brought excitement and uncertainty.
The two were speaking about American biotech company Moderna, which this week announced promising early results of its candidate vaccine.
On Monday, the Massachusetts-based company reportedly revealed that the first human testing phase of its vaccine, mRNA-1273, had shown positive results amongst its test group. The vaccine reportedly produced an immune response in the eight people who received it in low doses, which is similar to that observed in people recovering from the virus.
Another 17 participants reportedly had immune responses at a level similar or greater than recovered patients.
Moderna’s Israeli chief medical officer, Dr Tal Zaks, confirmed the promising results to Times of Israel. “We got the first results today […] and we are showing that it actually works. We are able to stimulate the immune system,” Zaks said.
He also reportedly confirmed that the next phase of testing on thousands of people would go ahead in July.
“By about the end of the year, the start of next year, there’s a reasonable likelihood that we’ll see this vaccine on the market, at least on the American market,” he said in an interview from Moderna’s headquarters.
Zaks said that the vaccine produced a similar response to the one naturally produced by patients who had recovered from the virus. Beyond that, higher doses created more antibodies than those created naturally. The company also reportedly said that the vaccine “was generally safe and well tolerated”, and that patients suffered no more than redness or soreness from the shots.
While most of the media has hailed the announcement as a major breakthrough, some are more conservative about the results. Experts reportedly told medical publication Stat News that they were waiting for more statistical evidence to back the success.
Shoul also expressed his reservations, and put the news into perspective, telling the SA Jewish Report, “Each step is enormous. The fact that there is a vaccine that has made it to this stage is a triumph, but the phase they’re in really only shows the safety of the vaccine in healthy people and whether antibodies are generated from it. We don’t really know more than that.”
He said that the vaccine had to pass multiple tests. “We know it’s safe for healthy, younger people, but we don’t know if it’s safe for older people, those who are immune-compromised, or children. The people who have been tested have no other conditions and received small doses. They showed no major side-effects. That’s all.”
Shoul stressed that this is a vaccine aimed at preventing healthy people from contracting the virus, making it almost impossible to compare the breakthrough with other strategies being developed.
“It’s a preventive strategy,” he said. “It prevents people from getting infected, unlike convalescent plasma or antiviral treatment which are therapeutic strategies. They’re very different paths in the bigger story.”
Shoul pointed out that this is simply one of many vaccines being developed concurrently, meaning that other major companies may also soon embark on testing phases like Moderna.
“Because the stakes are high and complications so huge, we don’t always have access to all the research that’s happening,” he said. “But we know there are other teams worldwide working on the same thing.
“This is one biotech that has issued a statement regarding early results, but it’s by no means the only one working on it.
“It mustn’t change our strategy and how we think about infection,” he said. “We can’t suddenly all go back to work or school, stop wearing masks, and believe it’s over. This isn’t a saviour yet. We must maintain common sense and follow advice regarding prevention.”
Said Van Zyl, “It’s uncertain as a messenger RNA (mRNA) vaccine has never been licensed to prevent a human infection. Nevertheless, scientists are excited about the potential of this novel strategy as it’s very clean. Once inside cells of the body, it produces only the specific antigen or protein to which the body should launch an immune response, and it may therefore be safer than other vaccines.”
“It may in future offer another approach to vaccination against other diseases even if it doesn’t prove that useful against COVID-19.”
It’s too early to tell “which horse may win the race, but unlike influenza, the virus evolves really slowly, which makes vaccine development somewhat easier”, Van Zyl said.
“Overall, I’m positive about the prospects of a vaccine, but the timeline is difficult to predict.”