In the middle of last year, the World Health Organization began promoting an ambitious goal, one it said was essential for ending the Pandemic: fully vaccinating 70 percent of the population in every country against Covid-19 by June 2022.

The world will fall short of the target by the deadline. As badly needed funding from the United States dries up and both governments and donors turn to other priorities, there is a growing sense of resignation among public health experts that high Covid vaccination coverage may never be achieved in most lower-income countries.

The reality is that there is a loss of momentum, according to Dr. Adewole, a former health minister of Nigeria who now serves as a consultant for the Africa Centers for Disease Control and Prevention.

Bangladesh, Bhutan, Cambodia and Nepal are some of the countries that have reached the 70 percent vaccination threshold. According to the Our World in Data project at the University of Oxford, many are under 20 percent.

About two-thirds of the world's richest countries have reached 70 percent. The United States is at 66 percent.

The consequences of giving up on high coverage could be severe. Public health experts say that abandoning the global effort could lead to the emergence of dangerous new variants that would threaten the world's precarious efforts to live with the virus.

It's imperative that countries use the doses available to them to protect as much of their population as possible, because the Pandemic is not over yet.

Some countries in the world, including some in Eastern Europe and the Middle East, have seen their vaccination rates stagnate in recent months. Africa's vaccination rate is the worst.

ImageVaccinations in Kathmandu Durbar Square in Nepal in 2021.
Vaccinations in Kathmandu Durbar Square in Nepal in 2021.Credit...Narendra Shrestha/EPA, via Shutterstock
Vaccinations in Kathmandu Durbar Square in Nepal in 2021.
ImageFilling out forms by cellphone light in the village of Bran, Romania, during a Covid vaccination marathon last year. Some Eastern European countries have seen their vaccination rates stagnate in recent months.
Filling out forms by cellphone light in the village of Bran, Romania, during a Covid vaccination marathon last year. Some Eastern European countries have seen their vaccination rates stagnate in recent months.Credit...Daniel Mihailescu/Agence France-Presse — Getty Images
Filling out forms by cellphone light in the village of Bran, Romania, during a Covid vaccination marathon last year. Some Eastern European countries have seen their vaccination rates stagnate in recent months.

Only 17 percent of Africans have received a primary Covid immunization. Half of the vaccine doses delivered to the continent have gone unused. The number of injections on the continent fell by 35 percent in March. W.H.O. officials said that mass vaccinations were being replaced by smaller-scale campaigns in several countries.

Some global health experts say the world missed a chance last year to provide vaccines to lower-income countries when the public was more fearful of Covid.

There was a time when people were very desperate to get vaccine, but it wasn't available. They realized that without the vaccine, they wouldn't have died.

The global vaccination campaign has been hampered by a lack of funding for equipment, transportation and personnel needed to get shots into arms.

Lawmakers in the United States stripped $5 billion from the coronaviruses response package because they were a key funder of the vaccine effort. Biden administration officials have said that they will not be able to provide support for vaccine delivery to more than 20 under-vaccinated countries without the funds.

Some public health experts think that the global vaccine campaign is still going strong. The number of Covid vaccinations being administered each day in Africa is still near a high despite the drop off from the February peak. Despite falling short of its goal, Gavi received a significant new round of funding pledges.

The White House plans to co- host a global Covid summit next month and there is hope that it will be an opportunity to raise funds.

The drop in public demand has led some health officials and experts to question whether the 70 percent vaccine target is feasible or even sensible.

Reported deaths from Covid-19 are low in Africa, although there is debate about how much of this is due to poor data tracking. The disease is not seen as a serious threat in many countries in the region because of the lack of health care resources.

Fifa Rahman, a civil society representative to a W.H.O.-launched group coordinating the global Covid response, said that many lower-income governments are turning their focus to their economies and other health issues. Everyone was asking where their vaccines were when the momentum was there.

ImageA refrigerator housing a fresh shipment of Johnson & Johnson’s Covid vaccines, overseen by Covax, the global vaccine clearinghouse, in Juba, South Sudan.
A refrigerator housing a fresh shipment of Johnson & Johnson’s Covid vaccines, overseen by Covax, the global vaccine clearinghouse, in Juba, South Sudan.Credit...Lynsey Addario for The New York Times
A refrigerator housing a fresh shipment of Johnson & Johnson’s Covid vaccines, overseen by Covax, the global vaccine clearinghouse, in Juba, South Sudan.
ImageHealth workers lining up for their shots in Johannesburg last year.
Health workers lining up for their shots in Johannesburg last year.Credit...João Silva/The New York Times
Health workers lining up for their shots in Johannesburg last year.

In rural areas of the Democratic Republic of Congo, where the reported Covid death rate is very low, there is a surge in measles cases threatening 20 million children. Christopher Mambula, medical manager for Doctors Without Border in East Africa, said that the government can't spare the resources to provide supplementary measles vaccinations this year. He said that it makes little sense to continue to divert resources to vaccine against Covid.

African governments have received more vaccines donated from wealthy countries, but their interest in ordering more has waned.

The African Union wants to have 70 percent of its population vaccined by the end of the decade. With countries slow to use donated vaccines, the bloc has not exercised its options to order more shots from Johnson and Moderna.

The South African drugmaker Aspen Pharmacare finalized a deal to bottle and market the Johnson & Johnson vaccine across Africa, a contract that was billed as an early step toward Africa's development of a robust vaccine production industry. The African Union and Covax have not placed orders yet, despite Aspen being geared up for production.

The world's largest vaccine maker, the Serum Institute of India, stopped production of Covid shots in December of last year, when its stockpile grew to 200 million doses, and another Indian firm stopped making vaccine in the face of low demand. The contracts with the Indian government ended in March.

Many lower-income governments adopted the 70 percent goal after the W.H.O. began promoting it. It was endorsed by the Biden administration last September.

There was still hope that achieving high levels of vaccination coverage would tame the virus, as it was believed that two doses of the vaccines from Pfizer and Moderna would offer very strong protection against even mild disease. The spread of the virus in Africa changed the calculus.

The vaccine regimen that was planned for the developing world did not offer much protection against the Omicron variant. More and more Africans gained protection against the virus from natural infections, which studies have shown works, as a result of the fact that sub-Saharan African countries were shut out of vaccine distribution for much of last year. According to new data from the W.H.O., at least two-thirds of Africans had been exposed to the virus before the Omicron wave.

ImageHealth workers in Sierra Leone prepared a cooler of vaccines to be delivered to the village of Kathantha Yimbo.
Health workers in Sierra Leone prepared a cooler of vaccines to be delivered to the village of Kathantha Yimbo.Credit...Finbarr O'Reilly for The New York Times
Health workers in Sierra Leone prepared a cooler of vaccines to be delivered to the village of Kathantha Yimbo.
ImageA UNICEF worker leaving a health facility in the village of Maar, South Sudan, after assessing its viability as a Covid vaccination site after flooding last October.
A UNICEF worker leaving a health facility in the village of Maar, South Sudan, after assessing its viability as a Covid vaccination site after flooding last October.Credit...Lynsey Addario for The New York Times
A UNICEF worker leaving a health facility in the village of Maar, South Sudan, after assessing its viability as a Covid vaccination site after flooding last October.

Some public health experts in Africa say the 70 percent goal is no longer worth it. Shabir Madhi, a professor of vaccineology and the dean of the faculty of health sciences at the University of the Witwatersrand, said that getting to more than 90 percent of people above the age of 50 would gain much more. More than two-thirds of South Africans are currently fully vaccine free.

Dr. Madhi said that South Africa could close down mass vaccination sites and double its efforts to find the most vulnerable at church services and government offices.

The W.H.O. encourages countries to focus on their most vulnerable citizens rather than vaccinating them all. 100 percent of health workers, 100 percent of older adults, 100 percent of pregnant women, and 100 percent of the people who fall into those highest risk groups have always been the aspiration.

The world has enough resources to do this, if countries want to.

Public health experts said that it would be unethical to give up on the 70 percent target over a longer time horizon, even though it is clearly not possible by the original deadline. They were frustrated by the growing gulf between rich and poor countries, as well as the regions where the majority of people still do not have one dose of vaccine.

The African Union's vaccine delivery program has two targets, one for high-income countries and one for low-income countries.

She said that there is still need for more protection from a high level of vaccine coverage, even though many people in Africa have been exposed.

She said that a good level of protection in England is not a good level in America. How can we not be aiming for the maximum? Get to the top of the tree by aiming for the sky.