Guidance for Evaluating and Updating Immunizations during the Domestic Medical Examination for Newly Arrived Refugees

Background

US-bound refugees, unlike immigrants, are not required to receive vaccinations before arrival in the United States. Therefore, many may not be fully up to date with ACIP-recommended immunizations at time of arrival. Refugees may have received vaccines before their displacement, from programs run by countries of asylum (depending on healthcare access), through vaccination programs and initiatives in refugee camps, or during the overseas health assessment as part of the Vaccination Program for US-Bound Refugees. Additionally, in settings with vaccine-preventable disease outbreaks, refugees may be required to receive specific immunizations before travel to the United States.

Vaccination Program for US-Bound Refugees

US-Bound refugees are offered some vaccines overseas through the Vaccination Program for US-Bound Refugees. This program was initiated to protect health, prevent travel delays due to disease outbreaks, and allow for more rapid integration into schools after arrival in the United States. US-bound refugees at participating sites are offered 1–3 doses in each vaccine series, depending on age, availability of appropriate vaccines, time to departure, and logistics. First vaccine doses are given during the overseas medical screening examination, approximately 3–6 months before departure for most refugees. Second vaccine doses are typically given 1–2 months after the first doses. Refugees who undergo repeat medical examinations before departure may receive additional vaccine doses. Vaccinations administered through this program are documented on the DS-3025 (Vaccination Documentation Worksheet). Age-appropriate historical vaccinations with valid documentation are also recorded on the DS-3025 in the “Vaccination Record” column.

Evaluating Vaccination Records for Arriving Refugees

During the domestic medical screening, clinicians should:

1. Review the overseas vaccination records for dates of administration, intervals between doses, and age at the time of vaccination.
   1. The DS-3025 will include vaccines given as part of the overseas vaccination program and a record of valid, documented historical vaccines presented at the time of overseas health assessment. Generally, any vaccines documented on this form can be accepted as valid and count toward the refugee’s US immunization record.
   2. Historical vaccination records may include camp vaccination cards, as well as records or booklets from other programs or clinics Whenever possible, overseas panel sites document valid historical immunization records in the “History” section of the DS-3025. Historical records are more likely to predict protection if the documented vaccines, dates of administration, intervals between doses, and the person’s age at the time of vaccination are comparable to ACIP recommendations [1]. Some documented historical vaccinations may be incompatible with ACIP recommendations (e.g., measles-containing vaccines given before 1 year of age, or monovalent measles vaccines rather than the measles-mumps-rubella [MMR] combination vaccine). Verbal reports of prior vaccination should not be counted toward the routine immunization schedule. Only valid, documented vaccine doses should count toward the immunization schedule.

      Frequently, vaccine names are documented in languages other than English, or the names or components of vaccines may be unfamiliar to US clinicians. Language translations are available from the Immunization Action Coalition [PDF – 2 pages] and the CDC Pink Book [PDF – 13 pages]. The Immunization Action Coalition also has published a list of vaccine manufacturers and product information.

2. Determine which vaccines are due based on ACIP recommendations, age, and immunization history.
   1. Space vaccine doses appropriately, taking into account the correct intervals between any historically documented vaccines and those to be given at the domestic screening (e.g., two live injectable vaccines such as MMR and varicella should be given on the same day or separated by a minimum of 28 days).
   2. TST or IGRA tuberculosis test may be administered simultaneously with live vaccines or deferred for 28 days after vaccination [1].
3. Determine whether revaccination is appropriate. Revaccination may be considered in some circumstances:
   1. Invalid or incorrectly documented historical vaccines (e.g., record indicates a vaccine dose was given before birth, taking into account possible transposition of month and day [dd-mm-yyyy])
   2. Clinician concerns about the validity of documented vaccines or falsification of records (rare)
   3. Severe pediatric malnutrition at time of immunization may impair adequate immune response. However, the immunology of malnutrition is poorly understood and data are limited. While most malnourished children can mount a protective immune response following vaccination, the timing, quality, and duration of their immune response may be diminished [2]. Some experts advise revaccination once the child’s malnutrition has resolved.

Decisions about revaccination are best made after the options available for various vaccines are discussed with the patient and/or caregiver. Tables discussing approaches to revaccination, including checking for serologic evidence of immunity and “catch-up dosing” are provided by CDC and by the American Academy of Pediatrics Red Book. Clinicians should be aware that adverse events attributed to excess immunization are rare and generally mild. Local adverse effects or reactions are more common with certain vaccines. All adverse events should be reported to the Vaccine Adverse Event Reporting System.

Vaccination Administration

Vaccinations should be given in accordance with ACIP recommendations. Both adults and children should be evaluated and their vaccine needs addressed during the domestic screening visit. See the ACIP childhood immunization schedules (including catch-up schedules), and adult immunization schedules. Although there is no specific limit to the number of vaccines that may be given during one visit, the decision about how many vaccines to give at one time should be agreed upon by the patient (or patient’s caregiver) and clinician. Combination vaccines can decrease the total number of injections and may be useful when administering catch-up vaccines. If the number of vaccines needed exceeds the number a patient is willing to receive at one time, the clinician may need to prioritize vaccines. Vaccine prioritization should be based on several factors including the patient’s risk of contracting or spreading specific infections, the number of antigens in a vaccine (e.g., a single shot with antigens for five infections or a vaccine with a single antigen), and patient concerns about certain vaccines. The clinician also should consider the compatibility of vaccines (live-virus vaccines should be given concurrently or separated by 28 days), minimum dosing intervals, and the number of doses required to complete a series.

Patients should be assessed for any potential contraindications to vaccination, including severe allergic reactions to a vaccine or vaccine component. Pregnancy or certain immunocompromising medical conditions should also be considered before administering live vaccines. Additional vaccines may be recommended for patients with certain underlying medical conditions. See the recommended schedules by medical indication for adults and children.

Serologic Testing before Vaccination

If vaccination records are unavailable, an age-appropriate vaccination schedule should be initiated. However, serologic testing for immunity (i.e., antibody testing) is an alternative when the provider believes the refugee is likely to have had a previous infection that conveyed immunity or if they received a full series of vaccines that was not recorded.

Multiple factors influence the clinician’s decision to check for serologic evidence of immunity before vaccination. Examples include:

• Cost of the vaccine course compared to serologic testing
• Likelihood of previous infection on the basis of the population prevalence or individual history
• Availability of antibody testing and acceptance that antibody presence confers immunity
• The number of doses needed to complete a series
• The level (titer) of antibody known to confer immunity
• The likelihood that the patient will return for results and further management

Healthcare professionals may choose to test for immunity in certain refugees (such as African adults who are likely to be immune to measles, mumps, and rubella, or hepatitis A). Cost-effectiveness will vary according to the prevalence of disease or immunity in the population, as well as the cost of serologic testing in different laboratories. More data are needed on population-specific vaccine-preventable disease prevalence rates to determine cost-effectiveness of serologic screening versus initiation of a vaccine schedule [3, 4]. Clinicians should be familiar with the appropriate serologic tests to order and how to interpret the results.

Special Considerations

1. Hepatitis B Virus (HBV)
   Most US-bound refugees are tested for HBV infection overseas using hepatitis B surface antigen (HBsAg). HBsAg results will be documented on the DS forms, typically in the remarks section of the DS-3026 (Medical History and Physical Examination Worksheet) and/or the DS-3025.
   HBsAg-positive persons do not receive HBV vaccination overseas. However, individuals are counseled about the infection and transmission prevention. HBsAg-negative persons are offered the hepatitis B vaccine. Most receive 2 doses before departure and may be due for the third dose after arrival. In this situation, serologic testing should not be performed. If serologic testing is performed, results should be interpreted with caution, as vaccination may cause temporary seroconversion (anti-HBs), which does not predict long-term protection. In addition, HBsAg testing should be delayed for at least 4 weeks after the final hepatitis B vaccination because the vaccine can cause a false positive HBsAg for up to 30 days. Therefore, serologic results can be difficult to interpret (and generally avoided) when an individual has received an incomplete hepatitis B vaccine series.
2. Varicella Serology
   The epidemiology of varicella in international settings differs from that in the United States. The median age of varicella infection varies throughout the world but generally occurs later in life in the tropics than in temperate climates (most children will not be infected, and it is common to find nonimmune adolescents and adults). Serologic screening of newly arrived refugees for varicella immunity before vaccinating is cost-effective, especially in older adults [5, 6]. Factors that commonly lead clinicians to vaccinate rather than screen for varicella antibody include:
   • Exposure to a person with varicella or herpes zoster
   • Younger age (6 years of age may be cost-effective in most populations tested [5])
   • Difficulty in arranging follow-up visits
   • Inability or lack of mechanism to pay for the screening test
   • School entry or work requirements
3. Hepatitis A Virus (HAV) Serology
   Additionally, the epidemiology of HAV in international settings differs from that in the United States. Most children coming from areas highly endemic for hepatitis A (most refugee populations) will have been infected (with minimal or no symptoms) and will have immunity. In some situations, testing for HAV infection may be more cost-effective than the two-dose vaccine series, although delays in receiving results and logistical challenges of repeat visits should be considered.
4. Poliovirus Vaccination
   All applicants for immigrant visas meeting the criteria outlined in the Addendum to Technical Instructions for Panel Physicians for Vaccinations: Polio are required to receive one dose of inactivated polio vaccine (IPV) within 12 months of travel to the United States. This requirement applies to all residents of and long-term visitors (i.e., >4 weeks) to countries identified to be infected with WPV1, cVDPV1, cVDPV2, or cVDPV3, with potential risk for international spread. Countries listed in the addendum are based upon WHO recommendations and are updated regularly.
   Those applying for US Refugee or Visa 92 or 93 status are not required to receive vaccinations before travel to the US. However, they may receive overseas vaccinations through the Vaccination Program for US-bound Refugees. Additionally, some may be required to meet other vaccination requirements separate from the immigration medical exam.

   Oral polio vaccine (OPV) received in or after April 2016 is bivalent (bOPV), protecting against polio types 1 and 3. Children with historical documentation of OPV (including on the DS-3025) given in or after April 2016 should be revaccinated with IPV [7].

Follow-up Care

While ongoing preventative healthcare may be unfamiliar to some refugees, most will be familiar with the importance of vaccination. Routine vaccinations also provide a good opportunity to establish and assure ongoing primary care. Refugees should be assisted in scheduling follow-up visits to complete their vaccinations.

Adjustment of status to permanent resident alien (“green card”) occurs one year after arrival in the United States. Proof of age-appropriate vaccination is required at the time of status adjustment. See the Vaccination Technical Instructions for Civil Surgeons for additional information on vaccination recommendations for adjustment-of-status applicants.