Vaccination alone not enough to control COVID-19

VACCINATION alone is not enough to achieve control of the COVID-19 pandemic, experts warn, proposing a raft of measures to avoid a crippling resurgence of disease once restrictions are lifted.

Professor Raina MacIntyre, head of the biosecurity research program at the University of NSW’s Kirby Institute, is one of 48 members of a new independent pandemic advisory group, OzSAGE, which includes experts from fields ranging from medicine and public health to engineering and software design.

“One area that has not been well addressed to date is ventilation and mitigation of airborne transmission, which is the dominant mode of transmission of SARS-Cov-2,” Professor MacIntyre told InSight+.

OzSAGE is calling for a “Ventilation and Vaccine-Plus” strategy for safely lifting COVID-19 restrictions, including urgent ventilation upgrades for schools and businesses, vaccination of children, continued mask wearing and third-dose booster vaccines for front-line health workers.

Other recommendations include mask mandates in schools for K–12 and the approval of rapid antigen home test kits.

OzSAGE also wants a higher target for full vaccination before restrictions ease: 80% or more of the population aged 12 years and over, rather than adults only at 70–80% as currently contained in the National Plan, which the group says corresponds to just 56–64% of the whole population. It has called for specified minimum geographic and population subgroup vaccination thresholds for reopening.

“Without ventilation, vaccine-plus and higher vaccine uptake, reopening at [the proposed] levels will turbocharge COVID-19, as seen in countries that lifted restrictions at about 60% whole population vaccination rates,” the group wrote in a report supplied to federal and NSW government stakeholders.

Pointing to OzSAGE’s “no-one left behind” principle, Professor MacIntyre highlighted inequalities in the vaccine rollout to date, particularly among Indigenous Australians.

“When COVID-19 spread from Sydney to western NSW, the vaccination rate was 7% in Wilcannia, and vaccines had actually been diverted from this part of NSW to Sydney,” Professor MacIntyre said.

“People in residential disability care were actually in phase 1a, so should have been vaccinated early, but were not,” she said.

“Prisoners are another group that concern us, as they are at high risk for outbreaks, but undervaccinated.

“Children are another group who are disadvantaged because those under 12 years will not be eligible for vaccination until at least 2022, when clinical trial results are expected in this age group.”

OzSAGE noted in its report that vaccines are highly protective against severe disease, but also warned that increasing evidence suggests efficacy wanes after about 6 months.

“Our health workforce was vaccinated in March 2021, and its immunity may be waning just as the COVID-19 epidemic in NSW surges,” the OzSAGE report says, emphasising the need to protect the health system.

Scientia Professor Guy Marks, a respiratory physician and OzSAGE member, said that in the short to medium term vaccination alone would not bring an end to the increase in cases.

“Vaccine coverage is not an all or nothing thing,” he told InSight+. “The vaccines will become more effective, we will get more coverage and we will have boosters, but that’s going to take some time.

“In the meantime, we need to do lots of different things – mask wearing, improving ventilation in indoor spaces, retaining some restrictions on mixing,” he said.

Professor Marks said for frontline health workers in south-west and western Sydney, the likelihood that things will get worse before they get better was causing great concern.

“Without the workforce, we won’t be able to deliver the care,” he said. “We need to do whatever we can to prevent a worsening of this epidemic over the short to medium term.

“Anything we do that does not achieve that is going to have serious consequences.”

The NSW Department of Education has announced a staged return to face-to-face learning, starting with kindergarten and year 1 students on 25 October.

OzSAGE’s Dr Greg Kelly, an intensive care specialist and paediatrician, said COVID-19 was most often a minor viral illness in children and less common in children than adults, as evidenced in a new report from the Australian National Centre for Immunisation Research and Surveillance, and others (here, here and here).

“The problem is that, as we’ve seen around the world, if you get a very large number of children infected, you can have kids with severe illness, critical illness and some will die,” he said.

“So what we’re seeing in the US, with extraordinarily high community rates of COVID-19, is they have substantial numbers of really sick kids.”

OzSAGE’s report notes that in Texas, where 52% of the population is vaccinated against SARS-CoV-2, paediatric intensive care units (ICUs) are full and children cannot get ICU beds.

“To avoid these risks, we need layers of mitigation that we can use which we can add or take away depending on how much virus is in the community,” Dr Kelly said.

“We know what works: things such as masking of children and teachers, vaccinating teachers and parents, improving ventilation or buying air filters where that’s not possible, a mix of face-to-face and online learning and rapid antigen testing.”

Dr Kelly said he was optimistic Australia could get the settings right, noting Victorian Premier Daniel Andrews this month flagged that school reopenings would hinge on ventilation assessments and use of carbon dioxide monitors and particle filters.

“We’ve got a tough few months ahead of us, but there are things we know work and we’ve really got to get started on those things,” he said.

“We would hate to see a situation in 6 months where we’ve fallen behind on these things in the way we fell behind on vaccination.”

A NSW Department of Education spokesperson said that in preparation for all students and staff returning to school, the department has begun a systematic review of the suitability of all learning spaces.

“The Department of Education is working closely with NSW Health and following its advice to ensure that schools comply with restrictions, protective measures and ventilation requirements,” the spokesperson said.