Question: Who was this American microbiologist who specialized in vaccinology that contributed to the development of the immunization vaccine against measles, mumps, and rubella (MMR vaccine)?

Context paragraphs:
MMRV vaccine: The MMRV vaccine combines the attenuated virus MMR (measles, mumps, rubella) vaccine with the addition of chickenpox vaccine or varicella vaccine (V stands for varicella).  The MMRV vaccine is typically given to children between 1 and 2 years of age.

Bio Farma: PT Bio Farma (Persero) is an Indonesian state-owned enterprise based in Bandung, Indonesia which produces vaccines and sera to support immunization in Indonesia and other countries.  Bio Farma has entered into a pre-qualification list of the World Health Organization (WHO).  Bio Farma vaccine produced vaccine consists of virus (vaccines against measles, polio and hepatitis B), and bacterial vaccines (vaccine DTP vaccine TT, vaccines DT, and vaccine BCG).  Bio Farma vaccines have supplied vaccines to multiple countries through UNICEF, PAHO and other organizations.

Hear the Silence: Hear the Silence is a 2003 semi-fictional TV drama based on the MMR vaccine controversy, which started when Andrew Wakefield published a paper claiming a possible link between the MMR vaccine and autism.  It debuted on December 15, 2003 at 9 PM on the British network Five.  The film, produced at a cost of about 1 million pounds, stars Hugh Bonneville as Wakefield and Juliet Stevenson as Christine Shields, a fictional mother who discovers the possible MMR-autism link when her son is diagnosed as autistic.  Stevenson's character begins telling doctor after doctor that her son seemed to develop autism soon after he received the MMR vaccine, but she does not receive any sympathy from them, nor does she receive any from her boss, or even her husband.  However, this all changes when she meets Dr. Wakefield, who believes her statements about the MMR vaccine causing her son's autism.  The film then shows fictional government officials "plotting" Wakefield's "demise", which they intend to bring about by portraying his research as flawed.  Although never documented in reality, the film depicts Wakefield being targeted by the government: his phone is tapped and his files are stolen.  The film attracted 1.2 million viewers on the first night it screened, considerably fewer than usual for Channel Five's films that debut at 9 PM, which often get more than 2 million viewers.

MMR vaccine: The MMR vaccine (also known as the MPR vaccine after the Latin names of the diseases) is an immunization vaccine against measles, mumps, and rubella (German measles).  It is a mixture of live attenuated viruses of the three diseases, administered via injection.  It was first developed by Maurice Hilleman while at Merck.

Rubella vaccine: Rubella vaccine is a vaccine used to prevent rubella.  Effectiveness begins about two weeks after a single dose and around 95% of people become immune.  Countries with high rates of immunization no longer see cases of rubella or congenital rubella syndrome.  When there is a low level of childhood immunization in a population it is possible for rates of congenital rubella to increase as more women make it to child bearing age without either vaccination or exposure to the disease.  Therefore, it is important for more than 80% of people to be vaccinated.

Vaxxed: Vaxxed: From Cover-Up to Catastrophe is a 2016 American film alleging a cover-up by the Centers for Disease Control and Prevention (CDC) of a purported link between the MMR vaccine and autism.  According to "Variety", the film "purports to investigate the claims of a senior scientist at the U.S. Centers for Disease Control and Prevention who revealed that the CDC had allegedly manipulated and destroyed data on an important study about autism and the MMR vaccine"; critics derided it as an anti-vaccine propaganda film.

Mumpsvax: Mumpsvax is a mumps vaccine made of mumps virus.  It is a product of Merck & Co., Inc.  The vaccine is a component of Merck's three-virus MMR vaccine.

Holly's Law: The Antibody Titer Law ( Holly's Law ) (NJSA 26:2N-8-11), passed on January 14, 2004.  The law gives parents a choice before they consent to a second dose of measles, mumps and rubella vaccine.  A Vaccine Information Statement (VIS) should be provided to the parents each time a vaccine is given.  Holly's Law, NJ Chapter 257.  C.26:2N-9b; " Documented laboratory evidence of immunity from MMR shall exempt a child from further vaccination for MMR, as may be required pursuant to Department of Health and Senior Services regulations."

Maurice Hilleman: Maurice Ralph Hilleman (August 30, 1919 – April 11, 2005) was an American microbiologist who specialized in vaccinology and developed over 40 vaccines, an unparalleled record of productivity.  Of the 14 vaccines routinely recommended in current vaccine schedules, he developed eight: those for measles, mumps, hepatitis A, hepatitis B, chickenpox, meningitis, pneumonia and "Haemophilus influenzae" bacteria.  He also played a role in the discovery of the cold-producing adenoviruses, the hepatitis viruses, and the cancer-causing virus SV40.

MMR vaccine controversy: The MMR vaccine controversy started with the 1998 publication of a fraudulent research paper in "The Lancet" linking the combined measles, mumps, and rubella (MMR) vaccine to colitis and autism spectrum disorders.  The claims in the paper were widely reported, leading to a sharp drop in vaccination rates in the UK and Ireland and increases in the incidence of measles and mumps, resulting in deaths and severe and permanent injuries.  Following the initial claims in 1998, multiple large epidemiological studies were undertaken.  Reviews of the evidence by the Centers for Disease Control and Prevention, the American Academy of Pediatrics, the Institute of Medicine of the US National Academy of Sciences, the UK National Health Service, and the Cochrane Library all found no link between the MMR vaccine and autism.

Supporting paragraphs: MMR vaccine Maurice Hilleman
Answer: Maurice Hilleman