Even a full year after the first COVID-19 vaccinations arrive in Israel, “nowhere near” all citizens will have immunity, a leading epidemiologist says.
Michael Edelstein said a reality check is needed, as people mistakenly assume that preliminary trial results showing around 95 percent efficacy mean that almost all Israelis will be immune to the coronavirus within months of the vaccine rollout.
“There is now light at the end of the tunnel — the problem is we just don’t know the length of the tunnel,” commented Edelstein, until recently a top official in the UK’s public health programs and now professor at Bar Ilan University.
He spoke to The Times of Israel on Tuesday after vaccine developers had reported promising clinical test data, including Moderna, which is claiming 94% efficacy, and Pfizer, which is claiming 95%.
Israel’s vaccine orders include these shots, the first of which are expected in early 2021. Meanwhile, Israel’s own vaccine developers have completed Phase 1 trials for their Brilife shot, concluding it is safe with “very minor” side effects, and hope to have some doses ready in the summer.
“The emergence of several safe and effective vaccines in such a short period of time is an incredible achievement and will be a game changer in the fight against the COVID-19 pandemic,” Edelstein said. “However, vaccines are not an overnight silver bullet and fully protecting populations against the virus will take some time.”
From key questions about how the vaccines will actually work in our bodies to seemingly “trivial” but potentially drastic factors like needle shortages, he outlined the challenges, and said that there is room for optimism — but a need for patience.
1. Vaccine for every Israeli in first year? Don’t bank on it
Politicians talk constantly of vaccine deals and progress for Israel’s locally made inoculation, which has just finished the first phase of clinical trials, but Edelstein says rollout is likely to be slower than expected.
Edelstein estimated that by the end of the first quarter of 2021, aside from China’s vaccines for domestic use, there will be enough vaccines worldwide for just 150 million people, which he noted is equivalent to less than half the population of the US.
As the number increases through the year, Israel will be well-placed to secure vaccines, but is unlikely to get enough for everyone who is willing to take a shot.
“This is a completely unprecedented scenario, and presents global supply challenges even though there are international efforts to scale up production in a way that has never been seen before in the world of vaccines,” he said. “Manufacturers are outsourcing to other manufacturers, their direct competitors,” including AstraZeneca tasking the Serum Institute of India with some of its production.
In reality, there are likely to be enough shots in the first year of vaccination for part of the nation, and they are likely to go to health workers, those at high risk, and various age groups starting with the oldest.
2. Shots are effective — but for what exactly?
Will a vaccine stop you from passing the virus to others, or just from getting sick yourself? It’s a key question that will determine the extent to which shots stop the pandemic during the long period between the start of vaccination and its end, but at this stage, there is simply no answer.
The nature of clinical trials is that they report on what seems to be the efficacy in protecting test subjects from getting COVID-19 compared to a group that received a placebo. But they have no way of testing whether trial subjects may have spread the virus to others.
“We don’t know yet whether the vaccines confers indirect protection by actually stopping transmission in addition to protecting people against severe disease,” said Edelstein. “This means we don’t actually know yet whether it will stop vaccinated people who encounter the virus from giving it to others.”
3. When will we need inoculating again? Will supplies meet demand?
Not only do manufacturers need to make a dose for almost everyone on Earth, but there are no clues as to when they may need to make a second dose for everyone.
Manufacturers have no way, at this point, to obtain clear information on how long vaccines stay effective, which means there is no understanding of whether there will be ongoing pressure for vaccines for repeat inoculation, and if so, how well vaccine producers would cope with that demand.
“In the world of vaccines there is a range,” Edelstein said. “Some vaccines protect for life; for example, if you get two doses of a Hepatitis A vaccine or measles vaccine. On the other hand if you get typhoid vaccine or flu vaccine you are protected for just a year or two. The time period there will have huge implications, and we know nothing yet about this in relation to COVID-19.”
4. Many Israelis will miss the second of the two shots
In an ideal scenario, everyone offered the vaccine will be fully protected. But that isn’t a realistic prospect, said Edelstein.
The vaccines currently ordered by Israel require two doses several weeks apart (the Israeli-developed vaccine, which won’t be ready until the summer at the earliest, is an exception as it needs just one shot).
With any two-part vaccination, a significant proportion of people simply don’t turn up for their second dose, Edelstein said.
People who take first doses of vaccines may miss the second due to disorganization, forgetfulness or a mistaken belief they are largely protected by dose one. He said that while there is no clear data yet on what level of protection such people would have, it can be assumed to be compromised by improper dosage.
Edelstein also predicted that the vaccination program will lag behind vaccine supply because of logistical issues. The vaccine will be given to groups according to priority level — probably calculated by risk and age bracket — and there will be delays as clinics wait for everyone in that bracket to come forward before moving to the next group.
5. Bottles, needles and freezers — logistics that can slow things down
Back on the issue of supply, Edelstein said that manufacturers could face the unthinkable scenario of having vaccine supplies ready, but no bottles or vials to put it in.
“There has never been so many doses being produced so rapidly by so many manufacturers and that can lead to shortages in vials, in syringes, and packaging,” he said. “It sounds very trivial but you cannot distribute a vaccine if you don’t have vials to put it in. A chain of events that normally takes five to ten years is being compressed, but the practicalities still take time.”
There are other logistical challenges to getting vaccines to clinics, Edelstein stressed, especially the “cold chain” storage to keep shots refrigerated, as required by most manufacturers.
The Pfizer vaccine is particularly problematic — it requires storage at extremely cold temperatures that pose a massive logistical challenge and could make it unsuitable for some countries, said Edelstein.
6. Hard choices on whom to inoculate first
Fighting the pandemic means getting people inoculated as soon as possible, and also carefully choosing who is first in line, said Edelstein.
The prevailing view today is that initial batches should go to medical staff and the elderly, but Edelstein said changing patterns of infection, with increasing numbers of young people compared to old people getting the virus, may suggest a rethink.
“The question is whether you want to protect those who are vulnerable against a circulating disease, or stop the transmission of the disease,” he said, observing that while the elderly are most vulnerable, younger people tend to be the biggest spreaders.
Therefore, if vaccines stop people transmitting the virus as well as contracting the disease, vaccinating younger people first may make sense.
“While it’s counterintuitive, vaccinating the young, who are least vulnerable, may be the quickest way to stop the outbreak,” Edelstein argued. He noted, however, that he isn’t necessarily advocating that path, though he thinks there is a logic to the argument — which indicates that vaccine priorities still need to be carefully considered.
“If you think this idea of vaccinating the young first is very far-fetched, it’s not, it’s a very commonly used approach for other vaccines.”
He noted that it had proved an effective strategy in 2006, when vaccinating children against pneumococcal disease protected the elderly, and said: “With flu, if you vaccinate children and achieve 75% coverage among them, this can give the elderly equal or even better protection from flu than delivered by vaccinating them directly.”
Policymakers should also consider the Israeli proposal to vaccinate super-spreaders first, he said.
But at the end of the day, Edelstein said, he is very hopeful.
“People shouldn’t expect everyone to be immunized in the next year, and shouldn’t throw away their masks yet — we will be wearing them for some time,” he said. “But we should also recognize that vaccines are being produced to high quality in record time, in what will go down in history as one of the biggest public health achievements on record.”
Source: Nathan Jeffay – TOI