The world’s long-term war against the pandemic has got yet another reassuring shot in the arm with US regulators approving the Johnson & Johnson vaccine, the third to get the nod in the country.
Results from a trial of about 44,000 participants show the J&J vaccine, the first major single-shot jab, was 66% effective in preventing moderate-to-severe Covid-19 globally.
The level of protection was 72% in the US after 28 days.
The J&J as well as Pfizer/BioNTech and Moderna vaccines differ on some fundamental factors.
The J&J vaccine involves a more conventional approach, using a common cold virus to introduce coronavirus proteins into cells to trigger an immune response.
But Pfizer/BioNTech and Moderna vaccines use the new messenger RNA technology to mimic the virus attack, both requiring two shots.
J&J’s vaccine could stay stable for at least three months at normal refrigerator temperatures, while the Moderna vaccine must be shipped frozen and the Pfizer/BioNTech must be shipped and stored at even colder sub-Arctic temperatures.
The bottom line: The J&J jab could make it easier to vaccinate larger numbers of people, especially in areas with poor transportation and storage infrastructure.
Here’s the key question in the early stages of vaccinations to fortify human defences against Sars-CoV-2 (the virus that causes Covid-19 disease): Will vaccines eliminate Covid-19 completely?
For perspective, only one human disease – smallpox – has been officially eradicated so far.
Smallpox was stamped out thanks to a highly effective vaccine and the fact that humans are the only mammals that are naturally susceptible to infection.
In comparison, Sars-CoV-2 is thought to persist in horseshoe bats, and has been known to infect minks, cats, gorillas and other animals. Wiping out the virus would require banishing it from every susceptible species, which isn’t feasible.
In countries that have successfully suppressed Covid-19 cases, disease elimination has been proposed instead.
Although international groups and a number of nations are promising to make vaccines affordable and accessible to all, doses will likely struggle to keep up with demand in a world of roughly 7.8bn people.
Also, none of the vaccines authorised in Western countries have been approved for children. It means, as of now, children are now included in the population needed to be protected.
As a matter of fact, even after the entire global population is inoculated, the virus may still loiter around in small clusters.
But some scientists have predicted that, once the endemic phase is reached and primary exposure to the virus is in childhood, Sars-CoV-2 may be no more virulent than the common cold.
Make no mistake, the world’s long-drawn war against Covid-19 is fought with lots of ifs and buts. That’s not because Sars-CoV-2 is exceptionally fatal, but it still remains exceptionally insidious.
Dr Anthony Fauci, the US government’s top infectious-disease expert, sounds optimistic.
“The looming question is, if the person who’s been vaccinated gets infected, does that person have the capability to transmit it to another person? Some studies are pointing in a very favourable direction,” he said in a White House briefing last week.
All said, vaccines are our best defence against the deceptive pathogen.
