Hongkongers out and about along the Tsim Sha Tsui waterfront on July 11. Photo: Felix Wong
Adrian Wu
Adrian Wu

Hong Kong should keep zero-Covid policy amid doubts over vaccines and herd immunity

  • Switching to a ‘live with it’ policy relies on vaccines alone doing the job, when new research suggests declining efficacies as new strains emerge. Hong Kong should wait and see

It is coming up to two years since the outbreak of Covid-19. Many people around the world are understandably tired of the disruptions to everyday life, not to mention the constant fear of sickness and death.

We are very fortunate in Hong Kong, as our city is a rare success in keeping the pandemic under control and minimising its impact on citizens.

Some people don’t seem to realise that the ability to conduct our daily lives almost as before, save for the travel restrictions, comes at a cost. It takes a collective effort to abide by the best infection control practices and give up certain liberties to make it a sustainable success.

Many argue it is time to walk back some restrictions, as nearly half the population will soon be fully vaccinated. They cite as examples certain Western countries which have lifted most restrictions and pursue a policy of “ living with the virus”.

We need to be careful in following their lead, since we don’t really know whether these policies are based on scientific rationale or political expediency. There has never been an example of a vaccine stopping a pandemic stone cold (except in films).

While vaccines have helped wipe out fearsome diseases such as smallpox, those efforts took decades. Unlike with SARS-CoV2, infections from viruses such as smallpox confer lifelong immunity, making herd immunity possible.

The best hope we had was to suppress Covid-19 transmissions while rapidly building up vaccine immunity. Many countries managed the first with painful lockdowns but squandered the hard-fought gains by relaxing restrictions too soon.

They essentially placed all their bets on vaccines alone doing the job. For those of us in the know, this is a tall order. Recent data show the Pfizer-BioNTech mRNA vaccine rapidly losing efficacy in reducing transmission and symptomatic disease, but it still seems to confer protection against severe disease and death.

While many political leaders expressed surprise at this development, it was entirely predictable. Every time the virus infects a new host, it has the opportunity to mutate to evade the host’s immune response.


Delta variant drives Covid-19 surge in southern US as unvaccinated are urged to get shots

Delta variant drives Covid-19 surge in southern US as unvaccinated are urged to get shots

Multiply this by, say, 30,000 times a day, and you will soon hit the jackpot. It is equivalent to a brute force attack in cracking an encryption code; the faster your computer can calculate, the sooner you can crack the code.

Letting the virus run rampant among a partially vaccinated population is like inviting every hacker in the universe to take a shot at your encryption. It is now a matter of outrunning the hackers with vaccine boosters.
The rapid development and deployment of vaccines is a huge feat in human ingenuity, even though efforts to develop vaccines against the coronavirus spike protein have been ongoing since the 2003 severe acute respiratory syndrome (Sars) epidemic.

But putting all our faith in vaccines against one specific target is like putting all your hope in Luke Skywalker hitting the Death Star’s reactor. Hollywood movies usually have a happy ending but life is rarely so simple.


WHO says no need for Covid-19 booster shots for now since vaccine supplies are low

WHO says no need for Covid-19 booster shots for now since vaccine supplies are low

The Western media tends to follow any mention of vaccines’ declining efficacy against infection and transmission with the phrase “but they are still holding up well against severe disease and death”. But for how long? I have not seen any credible scientific evidence to explain why the virus will just stop there.

The United States is advocating an mRNA “booster” injection for “all eligible people”. Worryingly, it was Pfizer which first advocated this approach, closely followed by President Joe Biden.
America’s top scientists have been strangely silent. If Biden is as competent in handling the pandemic as the Afghanistan troop pull-out, there is cause for concern.

Booster shots should wait until everyone has received jabs

And one wonders if any of UK Prime Minister Boris Johnson’s policy prescriptions in this regard is any better than his “get Brexit done” promise. How many people have received a third mRNA shot? What are their demographics? What is the efficacy? What is the rate of adverse reactions?

These questions should be answered before applying the booster to the general population. As far as I can see, none of these questions have been adequately addressed.

Hong Kong is right to continue pursuing a zero-Covid policy, because we have been successful so far. Why would we want to give that up in pursuit of an untested policy, even if it is advocated by some “advanced economies”? We should wait until at least the end of the year to see how these grand experiments turn out first.

Dr Adrian Wu is a specialist in immunology and allergy. He is currently in private practice at the Centre for Allergy and Asthma Care in Hong Kong