Where epidemiological and infectious disease experts had originally estimated that a vaccine for covid19 will, at its earliest, appear on the scene only 12 - 18 months after the onset of the pandemic, optimistic projections are that we may now get such a vaccine even before the year's end.

(Finding a cure and vaccine for covid 19, ST SAT) - which makes one concerned about their safety and efficacy.

When regulatory thresholds are not strictly adhered to, animal studies expediently compromised and safety profiles glazed over, the prospects of suboptimal vaccines coming onto an overtly expectant market loom great.

Governments and BigPharma continue to invest billions on vaccines to inoculate against covid19. Together with the prestige and first mover advantage the first vaccine brings, comes all the pecuniary profits and the triumphal flexing of superpower muscle as a show of who the next global hegemon will be.

It has taken several months before a clearer understanding of the covid19 virus has emerged and still, every month we learn something non intuitive about it.

It is not unlikely that the same experience will be repeated with vaccines rushed to the market.

The dilemma of the dengue vaccine is still fresh on our minds, where because of the four different dengue viral serotypes, the vaccine actually caused severe problems in patients who were infected with disparate strains before.

It is clear that the covid19 virus has different lineages and presently there is no guarantee that vaccines developed in one part of the world where one lineage is predominant will work, or worse still cause severe problems, in other regions where different viral lineages are principal.

Our ever-cautious health ministry saved us from any fallout caused by mass dengue vaccinations through not adopting the policy.

We yet again have to rely on it to perform all due diligence if and when covid19 vaccines appear on the horizon.

Yik Keng Yeong (Dr)