As countries try to expand their coronavirus vaccination campaigns and target uncertain supply chains, many of the first people to receive their photos are just now completing the final act of immunity, the second dose that increases the effectiveness of the two available American vaccines to about 95 percent.
Many healthcare professionals and others at high risk who received photos of Pfizer in mid-December are scheduled for their “booster” shot this week, which should be given 21 days after the initial dose.
The second shot carries many of the same logistical challenges as the first, from cold chain requirements to safe dose administration, plus the additional challenge of ensuring that the second dose is actually available to the right people according to the drug manufacturer’s dosing schedule.
“In the United States, we are still struggling in many ways with our ability to simply put the vaccine in people’s hands, so the second dose adds to the difficulty,” said Dr. Glenn Morris, director of the Institute for Emerging Pathogens at the University of Florida.
The availability of doses and progress in reaching all of them in phase 1A still varies considerably in the United States
“It’s really the unpredictability of shipments,” said Marilyn Guinan of Essential Hospitals, a group of more than 300 public hospitals in the United States.
So far, there do not appear to be widespread problems with people who miss their second dose, but experts say it is still early and the feasibility of a double mass vaccination will be tested in the coming weeks, especially as those who received the Modern Vaccine await their a subsequent shot that comes 28 days after the first.
More than 6.6 million people received their initial shot in the United States, according to the Centers for Disease Control and Prevention.
There are no national data on the degree of completion of the second shot.
“If you’re still having trouble keeping up with the crowds, it’s getting complicated, and that reduces your ability to give the first dose to more people, simply because you don’t have the logistics on the spot,” Morris said.
Healthcare workers sigh with relief
In Bellingham, Washington, a second arm pain came as relief for KIT nurse Kate Marn, who cares for patients with COVID-19 at PeaceHealth St. Joseph, the main hospital serving this quiet corner of the United States, the last stop before the international border.
“I’m just much more afraid of COVID than I am of the vaccine,” Marn said. “I’ve seen people die. I’ve seen people very, very sick.”
PeaceHealth operates clinics and hospitals throughout the Pacific Northwest and has already given the vaccine to about 3,000 workers in Washington.
Dr. Megan Ellingsen didn’t need anyone to convince her to show up for her second shot of the Pfizer vaccine.
Just before the hospice doctor fired her first shot, she performed a procedure on a dying cancer patient at his home.
“A week later, we found out there was COVID,” Ellingsen said. “I was in the little bathroom with him for 45 minutes and you can imagine how scary that was.”
So far, PeaceHealth has not experienced major problems with the second dose, according to hospital manager Charles Prosper.
“We had some restrictions on the supply of vaccines, but we see that this is increasing with greater capacity,” Prosper said.
Earlier this week, PeaceHealth did face a 2-day delay in the arrival of its second photos, but the healthcare system has already saved enough doses as a “buffer” just in case.
“To date, this actually keeps us in good shape without the risk of people missing their second dose,” says Prosper.
Supply chain “Angst” for some hospitals
But supplies are less secure in some parts of the country.
Florida has ordered hospitals not to save any doses, putting more pressure on manufacturers to deliver the second dose on schedule.
“It certainly raises some concerns,” said Mary Mayhew, president of the Florida Hospital Association.
“Everyone wants the staff to be scheduled to administer the shots, the meetings are ready, and it’s just a challenge to manage it all without having a certainty when it will arrive.”
So far, Pfizer’s second doses have arrived automatically on schedule, and Mayhew says she is confident the Moderna shipment will also come on schedule, although Florida hospitals have not yet received them.
With so many people already eligible to receive a shot in Florida, more than 4 million adults, Mayhew says the state is going through their supplies quickly.
“We have a lot of hospitals that are either without the vaccine or will be without the vaccine in a few days,” she said. “The bottom line is that demand is absolutely far above supply.”
As the spread of vaccines in the United States is slower than promised, some scientists and health officials say the second shot should be missed for now.
The United Kingdom and other countries follow a one-off approach, given the rapid number of cases and the emergence of a highly contagious variant of the coronavirus.
But the Food and Drug Administration rejected the proposal to change the dosing schedule, calling it “premature and not firmly rooted in the available evidence.”
The agency approved the Pfizer and Moderna vaccines on a two-dose course.
Glenn Morris of the University of Florida says there could be a compelling reason to delay the second dose if the vaccine spread is shaken in certain communities.
“We have implemented each country’s strategy for itself and in many countries, each county for itself, and so in these circumstances there may be cases where delaying the dose may make sense,” Morris said.
There is already a long-standing dilemma with vaccines that require multiple doses. Research shows that introducing an extra step leads to fewer people following, says Dr. A Mark Fendrick, who runs the Center for Value-Based Insurance Design at the University of Michigan.
“I’ve been worried about this problem with two shots since last summer,” he said. Fendrick says the good news is that one of the biggest barriers, money, has largely been removed because the vaccine is given for free, but there are still many other obstacles, whether it takes time to work, concerns about additional side effects or a feeling of “complacency that one is enough.”
He recommends that people customize reminders to receive the shot and small financial rewards for completing the last dose. “We cannot allow the last stage of this remarkable journey with the COVID vaccine, this so-called two-dose problem, to stop us from striving to get our lives back,” he said.