ATLANTA – HIV-positive men who have sex with men should be getting vaccinated against invasive meningococcal disease twice, but an alarming majority are only getting vaccinated once, according to a new study presented at a conference on STD prevention sponsored the Centers for Disease Control and Prevention.

“This analysis underscores the need for active patient recall in order to maximize return for second dose among HIV-infected [men who have sex with men], although [that] may be resource-intensive,” said Kelly Jamison, MPH , of New York City’s department of health and mental hygiene.

Ms. Jamison and her coinvestigators examined medical record data of HIV-infected men who have sex with men who visited New York City STD clinics between Oct. 5, 2012 and Dec. 31, 2014, looking for individuals who received their first meningococcal vaccinations during that time period. The primary endpoint was to find the rate at which individuals who received the first vaccination came back within 1 year (Dec. 31, 2015) to receive a second vaccination.

The study was prompted by the invasive meningococcal disease (IMD) outbreak that New York City experienced from 2010-2013, in which 22 cases were identified in men who have sex with men, of which 55% involved men who were HIV-infected. All IMD cases involved serotype C, with a case fatality rate that was three times what public health officials anticipated at the time.

Because of this, the city launched a meningitis vaccination campaign . Vaccination was recommended for all men who have sex with men who were residents of New York City and had high-risk sexual exposure after Sept. 1, 2012. In early October, STD clinics around the city began offering free MCV4 vaccines. By late November, the recommendations were updated to include men who have sex with men who lived in specific parts of Brooklyn and had experienced high-risk sexual exposure after Sept. 1. In March 2013, the recommendations were further updated to state that all HIV-infected men who have sex with men and all such men with high-risk sexual exposure should be vaccinated. In August 2013, after the outbreak was over, the recommendations were updated one last time to state that they were recommendations for “ongoing vaccination.”

“A single dose of MCV4 is not sufficient for HIV-infected persons, so a second dose is recommended to occur 8 weeks after the first dose, and in order to increase two-dose coverage among HIV-infected MSM, STD clinicians provided the date for person to return for their second dose on a vaccine card given to patients at time of their first dose,” Ms. Jamison explained.

In total, 1,212 individuals were included in study. Over the course of the study period, only 322 (26.6%) returned within 1 year for a second vaccination. In terms of individual years, 2012 experienced the highest rate of second vaccination returns, at 38.6% (P less than .001). Of the 322 who received the second vaccination, 144 (44.7%) came to the STD clinic specifically for the second dose, 69 (21.4%) asked for the second vaccination along with other STD services, and 109 (33.9%) were “opportunistically vaccinated while presenting for other services.”

Older men who have sex with men were more likely to return for their second vaccination, as only 63 (18%) of those who did were under the age of 30. Those aged between 30 and 39 years numbered 80 (23%), those between 40 and 49 years numbered 102 (33%), and those aged 50 years or older numbered 77 (40%), meaning that older men were two to three times more likely to get that second dose (P less than .001).

“We did see suboptimal return for second doses, but this may be an underestimate, [because] we were unable to capture second doses received at non-STD clinic providers,” Ms. Jamison noted.

Ms. Jamison did not report any financial disclosures for this study.