A description of the influenza vaccination program for health care workers in Vietnam

Background: In 2017, the Vietnam Ministry of Health conducted a demonstration project to introduce seasonal influenza vaccination to health care workers. A total of 11,000 doses of influenza vaccine, single-dose prefilled syringes, were provided free to HCWs at 29 selected hospitals, clinics, and research institutes in four provinces: Hanoi, Khanh Hoa, Dak Lak and Ho Chi Minh City. Methods: Before the campaign, a workshop was organized to discuss an implementation plan including technical requirements, cold chain, uptake reporting, and surveillance for adverse events following immunization. All sites distributed communication materials and encouraged their staff to register for vaccination. Following immunization sessions, sites sent reports on uptake and adverse events following immunization. Left-over vaccine was transferred to other sites to maximize vaccine use. Results: The average uptake was 57% for all health care workers, with 11 sites achieving 90% and above. These 11 sites were small with less than 500 staff, including 5 primary hospitals, 3 preventive medicine units, and 2 referral hospitals. Among the six biggest sites with over 1,000 staff, four sites had the lowest uptake (14%-47%). Most of the high-uptake sites were from the central to the south; only one site, a referral hospital, was from the north. After redistribution of left-over vaccine, only 130 vaccine doses (1.2%) were not used and destroyed. Based on factors that affected uptake, including registration levels, differing communication strategies, availability of vaccination, and commitment by health facility leaders, we recommended ways to increase health care worker coverage; recommendations to improve reporting adverse events following immunization were also made. Conclusions: The project demonstrated that it was feasible to conduct influenza vaccination campaigns among health care workers in Vietnam. Improvements in promotion of registration, more intense pre-planning, especially at larger facilities, and wider, more consistent availability of communication materials will result in increased efficiency and coverage in this program’s future expansion.

person was assigned to collect and consolidate lists of registered health care workers from all departments. Upon having the full registration list, sites informed MOH of the quantity of vaccines they needed.

Vaccines
Vaccine for this project, funded by the Cooperative Agreement IP000821 between U.S. CDC  Vaccine transportation and storage plan MOH had Phuc Thien Pharmaceutical Joint Stock Company distribute the 11,000 vaccine doses to the sites. The cold chain was maintained with temperature checks during storage, delivery, and receipt, which were documented. The cold chain system of the National Extended Program for Immunization was in place at two sites; other sites used their own cold chain system.
On a vaccination session day, vaccines were transported from cold storage to immunization sites in standardized cold boxes as per regulations. Unused vaccine at the end of the session was returned to cold storage. After each site completed their vaccinations, the vaccination team made a final record of vaccine used and any unused doses were later reallocated to other sites. The reallocation prioritized sites in the same province to minimize transportation costs. It was reported by all sites that the storage of influenza vaccines for this demonstration project did not cause any changes or impacts to the storage plan of other vaccines or the overall plan of the existing cold chain systems.

Immunization sessions
Vaccination teams were set up to carry out immunization; each team included one officer to list vaccine recipients and distribute vaccination certificates after immunization, one physician to screen participants, and one vaccinator. Smaller sites used one team, the largest sites used three teams, but most commonly, two teams were established for the immunization sessions. To avoid overcrowding, different departments came for immunization at different times. All sites reported that the arrangement for the campaign did not significantly affect their routine professional work.

Reporting and monitoring of immunization
All immunization sites were required to send a daily summary after each vaccination session and a final report by the end of the immunization campaign. The daily summary included a list of the day's vaccine recipients and any AEFI cases with appropriate details. AEFIs were monitored for 30 minutes at the immunization site or were reported to the immunization hotline within 24 hours after vaccinations, with daily summaries compiled into an all-site database. These requirements are in consistent with Ministry of Health's reporting requirements for routine immunization activities.
To ensure the timeliness and quality of reporting, each site assigned one person to consolidate daily the list of vaccine recipients, and coordinate the number of vaccines needed, used and remaining. If the number of health care workers vaccinated was lower than expected, reminders were sent out to registered HCWs; and the site also made extra efforts to encourage HCWs to come for vaccination.
This helped the site to reach as many registered HCWs as possible, and even reached HCWs who had not registered for vaccination. The timeliness of daily summaries and final reports from sites to MOH made transfer of left-over vaccines to other sites possible, greatly reducing vaccine wastage.
MOH sent staff to all sites to provide technical support and monitor activities. U.S.CDC joined MOH to monitor at some immunization sites. The monitoring and technical oversight helped identify drawbacks and implement timely adjustments.

Communication campaign
At each site, registered HCWs were provided a written summary about influenza and influenza vaccine. Some site leaders organized all-hands meetings where they advocated for the influenza vaccination campaign, highlighted the importance of vaccine and encouraged staff to get immunized.
During the vaccination session, vaccination staff advised HCWs on the benefits of influenza vaccine and its possible side effects. After getting the shot, each health care worker got a certificate of immunization (each site designed its own certificate). However, because all communication materials developed by MOH for this campaign were not completed before the vaccination started, most sites noted a lack of adequate communication materials, resulting in some HCWs not understanding the purpose of the vaccination campaign and the benefits of influenza immunization, and not registering 8 or coming for vaccination.

Results
Ten sites were selected at the beginning of the project. However, during implementation, some large sites, such as Bach Mai and Cho Ray Hospitals, had a lower than expected number of health care workers register for vaccination. This resulted in a considerable number of left-over vaccine doses.
For this reason, an additional 19 sites in the same four provinces/cities were added to utilize the remaining vaccine. Criteria for selection of additional sites were that the health facilities (i) must be located in the four selected provinces, and (ii) were willing to be part of this demonstration project. for face-to-face advocacy efforts. This also could be related to increased workloads at larger sites, making vaccination sessions more difficult for HCWs to prioritize and attend. The exceptions to this finding were the two tropical diseases hospitals, (which specialize in infectious diseases), that had better uptake, perhaps due to greater awareness of their occupational exposure to influenza.

4.
It is possible that that AEFIs, especially mild reactions, were underreported. Many HCWs did not stay for the entire 30 minute post vaccination monitoring time. Only seven of 29 sites reported any AEFIs and only one site, Ho Chi Minh City Hospital of Tropical Diseases reported more than 2 AEFIs. No serious AEFIs were reported, but because the program was conducted among HCWs in hospitals or clinics, it is unlikely serious AEFIs were missed.

5.
The storage of vaccines for this demonstration project did not affect the storage plan of other vaccines or the overall plan of the existing cold chain systems, given that the quantity of vaccine in the project were not a significantly large number.
Based on these findings, several key recommendations were made to improve coverage and efficiency of the immunization program for HCWs in Vietnam.
Greater promotion of the registration process and closer timing of the registration process to the vaccination session dates. A system should be developed for reminding HCWs, both registered and unregistered, of the dates and times of the vaccination sessions.

2.
Obtain hospital leaders strong active commitment to the immunization activity.

3.
Earlier and more intense planning at larger sites and specialized health facilities.
Management should ensure that HCWs have the time and opportunity to attend vaccination sessions, especially in more work-intensive settings.

4.
Communication materials should be improved, including more emphasis of the increased risks of exposure and benefits of protection to the HCWs, their families, and their patients. These materials should be made available well in advance and during registration and vaccination sessions.

5.
Ensure that HCWs are aware of AEFIs, emphasizing the extreme rarity of serious reactions while also stressing the importance for AEFI surveillance.

Conclusion
The project demonstrated that it was acceptable to conduct influenza vaccination campaigns among HCWs in Vietnam. Expansion of this program to more HCWs at more sites is likely achievable. Key findings and recommendations from this project could help improve coverage and efficiency of delivery in future influenza immunization efforts in HCWs.