Investigation: Misleading claims about masks and vaccines in Hong Kong’s 5th wave

Annie Lab looks into an article about Hong Kong’s COVID-19 fifth wave published by a known anti-vaccine website in the United States.

An article published by the U.S.-based, self-proclaimed research organization Brownstone Institute has made a few misleading claims about Hong Kong’s fifth wave of COVID-19, questioning the effectiveness of masks and vaccines using the city’s outbreak data as evidence.

The piece titled “Anatomy of the Hong Kong Disaster” was shared not only by the Institute’s social media accounts with thousands of followers but also by others. For example, it was tweeted on March 20 by Prashant Bhushan, an Indian public interest lawyer, who has over 2.2 million followers on Twitter.

The core of those claims were that despite a very high rate of mask use and vaccination, Hong Kong recorded among the highest number of confirmed cases and mortality rate in the world during the fifth wave — indicating that those measures did not work.

Hong Kong’s deadliest wave began at the end of 2021. During the course of four months and a half, the city of 7.4 million people experienced more than 9,000 COVID-19-related deaths and thousands of daily new cases on average during that time, according to the Hong Kong government.

Annie Lab investigated the claims made by the author Ian Miller in the article and found them misleading as Miller has largely misinterpreted the data without understanding the context.

Note on death rate: The Hong Kong government defines a COVID-19-related death as a deceased person whose first positive specimen was collected within 28 days of death. The underlying cause of death could have been unrelated to COVID-19. But not all deaths have been thoroughly investigated or accurately recorded during the fifth wave, as reported by local media.

First misleading claim: Masks did not work as protection

A mask mandate came into effect on July 15, 2020 in Hong Kong. Even now people over the age of two are required by law to wear masks in many public places. The rules are still mostly followed by the locals.

The article in question claimed that despite the mandate and the compliance to mask use, the number of infected cases and death rate surged in the city and therefore, masks are not effective in controlling the COVID-19 outbreak.

However, this claim is misleading. The article fails to include an important context — many of the infections during the fifth wave took place under the circumstances where citizens did not wear masks, such as when eating at restaurants, exercising or being at home.

Major clusters recorded at the beginning of the fifth wave, which mostly caused by Omicron variant of the virus, illustrate how it began.

In late 2021 quarantine-exempt aircrew from the Cathay Pacific, who were infected with an Omicron variant, are believed to have started a chain of infections, for instance, when two of them did not comply with mandatory home isolation and dined in a restaurant in Kowloon Tong.

A socially active mother of another crew member, who seems to have gotten the virus from the daughter, went dancing and had meals with friends, which created a cluster and a few lines of transmission.

One of the transmission chains also led to a scandal at a politician’s birthday party in early January during which many revelers were photographed to be not wearing masks.

Another big cluster was observed at Silka Seaview Hotel, a designated quarantine hotel where cross-infections among the hotel guests occurred, which later spread to their family members when they returned home.

In late January,  a “superspreader” event took place in Yat Kwai House of Kwai Chung Estate, a public housing complex in a densely-populated area. Hundreds of residents were infected in this housing estate alone. Local newspapers reported then that the virus can be transmitted through leaking pipes.

Miller used this graph, comparing Hong Kong’s mask compliance rate with its COVID-19 cases from October 2021 to February 2022 to misleadingly claim that wearing masks didn’t help prevent any infection.

Later on, more infections are recorded during the Lunar New Year when people visited their relatives’ home and had New Year food together.

“A lot of transmission occurs in mask-off settings like restaurants and households,” said Siddharth Sridhar, a microbiologist from the University of Hong Kong’s Medical School.

The original claim appeared in Miller’s article seems to ignore the many cases of mask-off transmissions in private places such as hotel rooms and inside people’s own homes as well as public gatherings involving eating.

Sridhar explained in an email to Annie Lab that even if people are wearing masks, it’s possible to get infected if the person has prolonged exposure to the COVID-19 patient.

He said universal masking probably reduces transmission to a variable extent, depending on the setting, ventilation, prevailing variant and other factors.

People should expect “universal masking to be less effective when Omicron is prevalent, but this does not mean zero protection,” he wrote.

Some experts suggest the situation could have been worse, had there not been mask mandates considering the high transmissibility of the Omicron variant.

Hong Kong government’s pandemic advisor David Hui Shu-cheong told the local media that Omicron is highly transmissible through airborne particles – four to eight times higher than the Delta variant.

Bloomberg reported that two fully vaccinated people could have transmitted infection across the hallway of a Hong Kong quarantine hotel as CCTV footage showed the two infected travelers had no direct contact, leaving air-borne transmission a possible explanation.

These observations indicated that masks do work but with limited capacity when it comes to Omicron. Instead of not wearing masks, as suggested by the Brownstone Institute article, experts in Hong Kong at the time recommended different mask-wearing strategies.

Another government advisor, microbiologist Yuen Kwok-yung suggested wearing one cloth mask on top of a surgical mask. Meanwhile, Hui said wearing a face shield on top of surgical masks also gives extra protection.

In case of wearing only one mask, the Wall Street Journal reported an infectious disease expert, Monica Gandhi, suggested wearing either N95, KN95, KF94 or FFP2 masks against the Omicron variant.

Sridhar also ranked the effectiveness of different kinds of masks — N95 or KN95 being the most effective, followed by double masks with surgical mask inside and cloth mask on top.

Second misleading claim: High vaccination rate did not protect Hong Kong from the fifth wave

Much of the vaccine misinformation stems from a misunderstanding of the statistics about vaccine effectiveness. Annie Lab has previously debunked some of these false claims (also here) related to COVID-19 vaccination.

Miller started one section of his article with a claim that Hong Kong had a high death rate despite high levels of vaccination. He cites the Hong Kong government’s dashboard, which said at the time he checked 82% of the city was fully vaccinated, and 91.4% had received at least one dose.

A closer look at the vaccination rates in Hong Kong’s population offers an explanation why his claim misleadingly oversimplifies what the data shows.

In Hong Kong, the vaccination rate of elderly citizens and care home residents, who were more vulnerable to the coronavirus, remained low until these groups were hit the hardest in the fifth wave.

The rate of fully vaccinated (two doses) population among the oldest age group was low in December 2021 before the fifth wave started. According to the government records, the vaccination rate for those 80 and above, which constitutes about 5.4% of the total population (about 400,000 people out of 7.4 million), was only 20% in the week of Dec. 19, 2021.

Even in late January, while the devastating fifth wave was making headlines every day in the city, only 22% of those who were living in a residential care home had taken the first shot, according to a social media post by Patrick Nip, the government official responsible for COVID-19 vaccination program.

As of April 4, 2022, less than 60% of those aged 80 and above were fully vaccinated, in contrast to 82.5% for 70 to 79 years old and 84.8% of the city’s overall population.

Hong Kong Vaccination Dashboard showed that more than 80% of Hong Kong residents are vaccinated with two doses. (Screenshot of Hong Kong Vaccination Dashboard)
The Hong Kong Vaccination Dashboard shows the percentage of population with at least first dose of vaccine in each age group. (Screenshot of Hong Kong Vaccination Dashboard)

Age, vaccination and other health conditions are significant factors in determining the severity of COVID-19 cases in Hong Kong.

According to the government’s website, as of April 12, the majority (71%) of the total COVID-19-related deaths in the fifth wave were among the age group 80 and above. Meanwhile, 73% of cumulative deaths were among the people who were unvaccinated.

In Hong Kong, most of the deceased cases are from the 80+ age group whose vaccination rate is low. (Screenshot of Hong Kong government website)

Poor infection control and low vaccination rate caused the residential care homes in Hong Kong to become an epicenter of the city’s COVID-19 infections.

In the middle of the fifth wave, there were outbreaks in more than 97% of care homes for the elderly and 85% for the disabled, according to the Social Welfare Department.

A provisional data analysis report by the government shows 56% of all fatal cases came from care homes for the elderly and for people with disabilities. Moreover, 92% of the people who passed away with COVID-19 had a history of chronic disease.

The government data analysis shows that the majority of the fatal cases were unvaccinated. (Screenshot from Provisional Data Analysis on COVID-19 Reported Death Cases)

The data analysis also makes it clear that the fatality rate among the unvaccinated is significantly higher in all different age groups.

Data analysis from the Hong Kong government shows that fatal cases related to COVID-19 were mainly unvaccinated cases. (Screenshot from Provisional Data Analysis on COVID-19 Reported Death Cases)
Third misleading claim: Vaccination is not effective for the elderly

In the article in question, Miller does acknowledge it’s possible that improving the vaccination rate among the elderly may help Hong Kong in its fight against the fifth wave. However, he follows this up with a statement challenging this notion.

His argument is that the U.S. has had high death rates even though it has had a higher vaccination rate among the elderly. In his view, it appears to contradict the assertion that the low vaccination rate for the elderly is what led to the high COVID-19-related death in Hong Kong.

This reasoning is also misleading as the statistics from the U.S. indicates a different story.

While the population of the elderly in the U.S. has a higher vaccination rate compared to some other places — it is at 89.5 percent as of April 13 — there remains more than 10% of unvaccinated elderly who are still at very high risk.

The 2019 census estimates there are about 54.1 million people aged 65 and older in the country. The statistics from the Center for Disease Control (CDC) shows 10% of that population isn’t vaccinated.

It means about 5.4 million people in that age group are at high risk of death or hospitalization when they catch COVID-19.

In January 2022, the COVID-19 task force at CDC concluded that those unvaccinated were nine times more likely to die from COVID-19 in the U.S. during the country’s last wave than those who were vaccinated.

Those 65 and older who received at least two doses of a COVID-19 vaccine had a “94% reduction in risk of COVID-19 hospitalizations,” according to the CDC.

(Source: US Center for Disease Control)

“In the U.S., as in Hong Kong, deaths in elderly were concentrated in unvaccinated individuals,” Sridhar said. “Even if you have 70% to 80% vaccination rates in the elderly, that still leaves a huge number of individuals unvaccinated due to the large population.”

“Also, deaths can still occur in some vaccinated individuals who have health conditions not allowing them to mount good immune responses. Vaccine effectiveness against death is very high, but is not 100 percent,” he added.

Fourth misleading claim: A vaccination rate of over 100% indicates unreliable data collection

Miller claimed that the figure shown on the Hong Kong government’s website was not reliable because it shows the vaccination rate for those aged 40-49 was over 100%.

This claim does not understand what the data shows in the Hong Kong context. The vaccination rate was over 100% because the population is estimated based on the number of residents while many non-residents can also get vaccinated in the city under the COVID-19 Vaccination Programme.

Miller uses a chart from the Hong Kong official website where the vaccination rate for the 40-49 age group is above 100 to question the reliability. The data on the chart has been updated since and no longer shows a vaccination rate higher than 100% as of now.

The Hong Kong authority explains that those non-Hong Kong residents who were eligible to receive vaccination were not part of the baseline population. In addition, the baseline population itself is an estimate and therefore, there may be deviations from the actual situation, which led to the vaccination rate going higher than 100%.

Since then the base population has been updated with a new provisional estimate of the end-year population in 2021 provided by the Census and Statistics Department.

Non-Hong Kong residents who are eligible to get vaccinated in Hong Kong are shown in the graph. (By Annie Lab)

Late last year, the Brownstone Institute also published an article questioning the efficacy of vaccination against COVID-19 with various claims but they have been debunked by a U.S. fact-checking organization Lead Stories.