WHO Expert Group On Immunization Highlights Global Vaccination Progress, Challenges

The World Health Organization’s Strategic Advisory Group of Experts (SAGE) on Immunization met from 23-25 October to review progress and recommendations for the Global Vaccine Action Plan, including the need for guidance on the use of Ebola vaccines in emergencies, the contribution of human papillomavirus (HPV) vaccination toward eliminating cervical cancer, and the current status of polio and measles eradication, according to a press briefing.

“SAGE is the principal advisory group to WHO for vaccines and immunization,” and is “charged with advising WHO on overall global policies and strategies, ranging from vaccines and technology, research and development, to delivery of immunization and its linkages with other health interventions,” according to the WHO website.

SAGE held a virtual press briefing on 26 October to share the results of their meeting, and to respond to questions. The audio from the press briefing can be found here [mp3].

Present at the press briefing were Alejandro Cravioto, chair of the SAGE group on Immunization, Joachim Hombach, executive secretary of SAGE, and Martin Friede, director of the WHO Department of Immunization, Vaccines and Biologicals.

“We had initially a high-end view of the situation of immunization around the world, and the issues that are confronting us in this field in the next months and years,” Cravioto said on the SAGE meeting. “The main conclusions of these discussions were related really to the situation of both the supply of these vaccines, their use in different populations, and especially the prospects we have on how vaccination against these diseases will actually help us to control them in the future.”

Status of the Global Vaccine Action Plan

At the meeting, SAGE held an annual review of progress on the global immunization efforts at the meeting, and Hombach shared some of the results, which indicate slow progress on increasing coverage, and a tenuous hold on past gains.

“While, overall, we have achieved very high levels of vaccination, it is very difficult to further increase coverage, and what we have seen, and what the report has shown is that there is the risk that hard-won gains that have been made over the years will be lost, if for instance we have insufficient commitment by countries, or it we have fragile countries, as we have seen quite a bit in the past,” Hombach said.

“We have seen, unfortunately, last year, a significant number of outbreaks, which are a sobering reminder that no country really should stop investing in immunization,” he said.

In addition to sustaining and increasing investment in immunization, Hombach said that there was discussion at the SAGE meeting “to link immunization efforts with the universal health coverage agenda, as well as the [UN] Sustainable Development Goals.”

Ebola Vaccine: Safe for Pregnant Women?

On the vaccination of pregnant women, Cravioto shared information on the status of Ebola vaccination guidelines. “There had been a number of women who had been inadvertently vaccinated, either because they didn’t know they were pregnant, or the vaccinators didn’t know that they were pregnant, and they have been followed up, but this is a small group that doesn’t allow us to reach any clear conclusions.”

The vaccine, Cravioto explained, “is made of a live virus, that replicates, and that is a serious consideration for its use during pregnancy.” This vaccine, developed by Merck, has been very effective in the West Africa outbreak, as well as in the current outbreak in the Democratic Republic of Congo, he explained.

“So, what we are trying now to indicate is on one side, what is the risk for a woman not to be vaccinated, while the others in the group are vaccinated,” Cravioto said, and expressed that based on current evidence, this risk appears to be low.

“We hope that within the next months there might be more information coming from a more detailed analysis of the women who have been followed up after being vaccinated while pregnant, to be able to really say whether the vaccination is safe in this group,” Cravioto said. “In the end, of course, it will have to be an informed consent decision of the woman, if she would like to be vaccinated or not.”

Another Ebola vaccine is currently in development by Johnson & Johnson, and Cravioto expressed hope that there will be a “successful phase of studies” on this vaccine “so that we can have a second product available to use in these outbreaks, but also to use these vaccines in a preventive way,” he said.

Scaling-up HPV Vaccinations to Prevent Cervical Cancer

Cravioto also shared some of the discussions from the SAGE meeting on the issue of the limited availability of the human papillomavirus (HPV) vaccine, and how that can be addressed.

“We have a constraint of supply that we need to deal with,” Cravioto said. “There is not enough vaccine.”

“Both manufacturers [of the HPV vaccine] were in the room with us at the SAGE meeting, and both offered their help to be able to get a solution soon to this problem,” he said. These manufacturers will “ramp up production so that we do have, in the near future, enough vaccine to be able to use in all the countries that decide to either start, or continue [HPV vaccination programs], and to increase the vaccination of girls, preferably, so that we can have a real impact in the final goal that we have, which is really the elimination of cervical cancer in women.”

This limited supply, Cravioto explained, should be focused on countries that have the highest rates of cervical cancer, in order to have the greatest impact in the shortest possible time.

“We did look into the possibility of changing the numbers of doses, but the studies to do that, to make a recommendation, are not yet complete,” Cravioto said, explaining that changing the recommended dose could perhaps stretch the limited supply of the vaccine, to be able to vaccinate more people.

“For the time being,” he said, “what we are waiting for are more trials that are being conducted in places like Costa Rica, that might give us a real idea of a single dose instead of two, which is the current recommendation.”

Eradicating Polio and Measles: Fragile Gains

Regarding the polio eradication program, Cravioto said the issue is “how we complete the task.” There should be enough supply of injectable polio vaccine to vaccinate the new children, he said, and hopefully to also vaccinate children who have been left unvaccinated, with the possibility of reducing the dose of the vaccine to be able to vaccinate more children.

The countries where polio is still present are Afghanistan, Pakistan, and Nigeria, he said.

On measles, Hombach noted that there have been major measles outbreaks this past year, in particular in Venezuela. He said that this “led SAGE again to highlight the fragility of the gains that we have made in relation to our cause on measles elimination, and really the urgent need to sustain these efforts and actually to further prioritize measles on the global public health agenda.”


Image Credits: WHO.

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