Covid-19 vaccine may involve 2 doses

Health experts in the US say that when a viable coronavirus vaccine is found, it may need to be administered in 2 separate doses, in order to be effective. This throws up all sorts of logistical problems, with Kelly Moore, a health policy professor at Vanderbilt University, expressing concern over procurement issues and the difficulty in getting people to show up not once, but twice.

“There’s no question that this is going to be the most complicated, largest vaccination programme in human history, and that’s going to take a level of effort, a level of sophistication, that we’ve never tried before.”

Meanwhile, the US Food and Drug Administration has not ruled out the possibility of giving emergency approval to a vaccine candidate before it has finished the necessary safety and effectiveness trials. China and Russia have already done this, a move that has been criticised by health officials around the world, including the US.

Stephen Hahn, Commissioner of Food and Drugs Administration, says any request for emergency approval has to be made by the vaccine developer. He insists he is not bowing to pressure from US President Donald Trump, who has previously said the US may have a vaccine ahead of November’s presidential election.

“If they do that before the end of Phase Three, which involves large-scale human testing, we may find that appropriate. We may find that inappropriate, we will make a determination. This is going to be a science, medicine, data decision. This is not going to be a political decision.”

The announcement comes as Phase 3 trials continue on vaccine candidates from 3 companies. AstraZeneca has teamed up with researchers at Oxford University, Moderna is working with the US National Institutes of Health, while Pfizer is partnering with BioNTech. Half of those taking part in the trials receive the vaccine candidate, while the other half are given a placebo. It normally takes months before results can be properly evaluated.

Meanwhile, Nada Sanders, a professor of supply chain management at Northeastern University, is concerned about logistics, should 2 separate doses of the vaccine be required.

“We’re looking at double shots. That’s twice the amount. Doubling is a huge supply chain issue. You have to double everything in the supply chain. The syringes, can they double up? Can the vials double up? Can the stoppers double up? Can the needles double up? Everybody has to double up, and then they all have to get it in time at the various entities along the supply chain.”

She points to the PPE crisis at the start of the outbreak, and the shortage of testing kits.

“We’re talking about such exactness, and we couldn’t get PPE right, so I’m concerned. There are many weaknesses across this supply chain, many. If we don’t address this now, the probability of failure is very high.”

In addition, Nelson Michael, from the Centre for Infectious Diseases Research at Walter Reed Army Institute of Research, says getting people to come twice to be vaccinated may prove a big ask. While 40% of Americans say they will refuse to have any Covid-19 vaccine, Michael says even getting those not oppposed to vaccination to come twice may prove a challenge. They may have to take time off work twice, wait in line twice, and put up with side-effects twice.

“These are the sorts of things that I think we need to think about, to make sure that we can incentivise people to come back, to make it as easy as possible for them to adhere to a two shot regimen.”

Meanwhile, Eric Topol from the Scripps Research Translational Institute, has taken to Twitter to hit out at the idea that a vaccine could be approved without completing clinical trials, accusing Hahn of capitulating to Trump’s demands.

“It is f*cking outrageous to expedite any approval of a #SARSCoV2 vaccine, irrespective of @SteveFDA’s subservience to Trump. We will not know about safety for many months.”

SOURCE: Bangkok Post | CNN